Red Betty Boop Heart Cake

My niece walked into the kitchen and spotted the Betty Boop magnet on the fridge, then asked if we could put her on a cake. That simple question turned into this playful heart-shaped dessert with a chocolate silhouette perched on top like a little edible work of art. The red crumb is soft and buttery, the frosting tangy enough to balance all that sweetness, and the crisp chocolate cutout adds a snap that makes every slice feel special. I had never piped a character outline before, but watching it harden on parchment felt oddly satisfying. Now every birthday request includes some version of this cake.

I baked this for a retro-themed potluck and watched grown adults argue over who got the slice with Betty Boop's face. One friend carefully peeled the chocolate off and ate it separately like a candy bar. Another used her phone flashlight to photograph the red crumb before taking a bite. The whole thing felt less like serving dessert and more like unveiling a surprise, which is exactly what a good cake should do.

Ingredients

• Cake flour: Sifting this fine flour gives the crumb a soft, delicate texture that regular all-purpose just cannot match.
• Natural unsweetened cocoa powder: Just a touch deepens the red color and adds a faint chocolate undertone without overwhelming the vanilla.
• Baking powder and baking soda: The combo creates lift, and the vinegar reaction with baking soda makes the crumb light and airy.
• Fine sea salt: A small amount sharpens all the other flavors and keeps the sweetness from feeling flat.
• Unsalted butter: Room temperature is key so it creams properly with the sugar and builds that fluffy base.
• Granulated sugar: Creaming it with butter traps air and gives the cake structure and tenderness at the same time.
• Large eggs: Let them warm up on the counter so they blend smoothly without deflating the batter.
• Buttermilk: The acidity tenderizes the crumb and gives the cake a slight tang that pairs beautifully with cream cheese frosting.
• Red gel food coloring: Gel is more concentrated than liquid, so you get vibrant color without thinning the batter.
• Pure vanilla extract: Use the real stuff for a warm, rounded sweetness that artificial vanilla cannot replicate.
• White vinegar: This activates the baking soda and creates tiny bubbles that make the crumb extra light.
• Cream cheese: Must be room temperature or it will clump and leave you with lumpy frosting no matter how long you beat it.
• Powdered sugar: Sift it first to avoid gritty frosting and make spreading silky smooth.
• Dark chocolate or candy melts: Melted gently, this forms the crisp silhouette that adds texture contrast and a little drama to every slice.

Instructions

Prep the pans:

Preheat your oven to 350°F and grease two heart-shaped pans, then line the bottoms with parchment so the cakes release cleanly. This step saves you from broken hearts later.

Mix the dry ingredients:

Whisk together the cake flour, cocoa powder, baking powder, baking soda, and salt in a medium bowl. Set it aside while you work on the wet ingredients.

Cream the butter and sugar:

Beat the butter in your stand mixer for a minute until smooth, then add sugar gradually and keep beating for two to three minutes until the mixture looks pale and fluffy. This traps air and builds the cake's structure.

Add the eggs:

Drop in one egg at a time, beating on low speed after each addition just until blended. Scrape down the bowl sides so nothing hides in the corners.

Color and flavor:

Stir in the red gel food coloring, vanilla extract, and white vinegar until the batter is evenly tinted. The color will deepen as it bakes.

Alternate wet and dry:

With the mixer on low, add one-third of the dry ingredients, then half the buttermilk, mixing just until incorporated. Repeat with another third of dry, remaining buttermilk, and finish with the last third of dry ingredients.

Activate the baking soda:

In a small cup, combine one teaspoon vinegar with the baking soda, then gently fold it into the batter. The foam means it is working and will create a tender crumb.

Fill and bake:

Divide the batter evenly between the prepared pans and smooth the tops with an offset spatula. Bake on the center rack for twenty-five to thirty minutes, or until a toothpick inserted in the center comes out clean.

Cool the cakes:

Let them cool in the pans for ten minutes, then run a thin knife around the edges and invert onto wire racks. Remove the parchment and let them cool completely before frosting.

Make the frosting:

Beat the room-temperature cream cheese and butter together for two minutes until smooth, then gradually add the sifted powdered sugar, a pinch of salt, and vanilla extract. Beat on low until fluffy and combined.

Assemble the layers:

Level the cake domes with a serrated knife if needed, then place one heart layer on a cake board. Pipe or spread about three-quarters cup of frosting over the top, add the second layer, and press gently.

Crumb coat:

Apply a thin layer of frosting over the entire cake to seal in crumbs, then chill for ten minutes. Add a final smooth layer of frosting and use an offset spatula to create swirls or leave it sleek.

Pipe the silhouette:

Place your Betty Boop stencil under a sheet of parchment, then pipe or brush melted dark chocolate over the outline. Let it set at room temperature or chill for ten minutes until firm.

Add the chocolate cutout:

Carefully peel the chocolate silhouette from the parchment and lift it onto the center of the cake. Press gently so it sticks to the frosting.

Final touches:

Decorate the edges with frosting rosettes, edible glitter, or red sugar pearls if you like. Chill the cake for thirty minutes before serving to let the frosting set, then slice with a warm, clean knife for neat hearts.

Save

The first time I set that chocolate Betty Boop on top of the frosted cake, my daughter clapped like I had just pulled off a magic trick. She took a photo before anyone could cut into it, and that picture still lives on our fridge under the same magnet that started the whole idea. It is funny how a little whimsy can turn a simple cake into something people remember long after the plates are empty.

Storing and Serving

This cake keeps beautifully in the fridge for up to four days if you cover it loosely with plastic wrap or store it in a cake keeper. The cream cheese frosting firms up when chilled, so let slices sit at room temperature for about ten minutes before serving if you want that soft, creamy texture back. I like to slice it with a knife dipped in hot water and wiped dry between cuts, which keeps the layers clean and the frosting from smudging.

Customizing Your Cake

You can swap the dark chocolate for white chocolate dyed black with oil-based food coloring if you want a brighter contrast against the red frosting. I have also used this same batter to make cupcakes, which bake in about eighteen minutes and are easier to serve at parties. If you do not have heart-shaped pans, two round nine-inch pans work just as well, you just lose the built-in romance of the shape.

Troubleshooting and Tips

If your cake domes too much in the center, your oven might be running hot, or you filled the pans unevenly. An oven thermometer is a cheap fix that saved me from many lopsided layers. If the frosting feels too soft to spread, chill it for fifteen minutes, and if it gets too stiff, beat in a teaspoon of milk until it loosens up.

• Always sift your powdered sugar or you will spend twice as long trying to smooth out lumps in the frosting.
• Let your melted chocolate cool slightly before piping or it will spread too thin and crack when you try to lift it.
• If you are nervous about freehand piping, trace the Betty Boop stencil with a food-safe marker on parchment and follow the lines with chocolate.

Save

This cake has become my go-to when I want to make someone smile without spending all day in the kitchen. The Betty Boop silhouette might look fancy, but it is just melted chocolate on parchment, and that little trick turns a homemade dessert into something that feels like a gift.

Recipe FAQs

→ Why use vinegar in the batter?

The vinegar activates the baking soda, creating tiny bubbles that result in a lighter, more tender crumb. This classic technique also enhances the red color development and adds subtle tang that complements the cream cheese frosting.

→ Can I make the chocolate silhouette ahead of time?

Absolutely. Prepare the dark chocolate outlines up to a week in advance, store between parchment paper in an airtight container at room temperature, and carefully place them on the frosted cake when ready to serve.

→ What if I don't have heart-shaped pans?

Use round 9-inch pans and cut heart shapes from the cooled layers using a cardboard template. Alternatively, bake in square pans and cut hearts, or use standard rounds and decorate with the Betty Boop silhouette on top.

→ How do I prevent the red color from fading during baking?

Gel-based food coloring is heat-stable and concentrated, so it maintains vibrancy better than liquid drops. Avoid overbaking, as extended oven time can dull colors. The acidic environment from buttermilk and vinegar also helps preserve red tones.

→ Can I freeze the unfrosted layers?

Yes, wrap cooled layers tightly in plastic wrap, then foil, and freeze for up to 3 months. Thaw overnight in the refrigerator before frosting. The moisture from buttermilk keeps them tender even after freezing.

→ Why is room-temperature ingredients important?

Cold butter and eggs can cause the batter to curdle or seize, creating uneven texture. Room-temperature ingredients emulsify smoothly, trapping air bubbles that ensure consistent rise and that signature velvety softness.