Ingredients

1 cup butter (at room temperature)

2 ½ cups granulated sugar

1 tablespoon vanilla extract

2 large eggs (at room temperature)

4 large egg whites (at room temperature)

1 cup buttermilk (at room temperature)

3 cups cake flour

2 teaspoons baking powder

½ teaspoon salt

Red food coloring

Blue food coloring

Instructions

Step 1: Preheat your oven to 350°F (175°C). Grease and flour a 12-cup Bundt pan, then set it aside.

Step 2: In a stand mixer fitted with a paddle attachment or using an electric mixer, beat together the butter and granulated sugar until well combined and creamy.

Step 3: Add the eggs and egg whites one at a time, mixing well after each addition to ensure they are fully incorporated.

Step 4: Stir in the vanilla extract until evenly mixed.

Step 5: Mix in the buttermilk until the batter is smooth and well combined.

Step 6: Sift together the cake flour, baking powder, and salt. Add this dry mixture to the wet ingredients and stir on low speed just until incorporated; avoid overmixing.

Step 7: Scoop out 1 ½ cups of the batter into a separate bowl for the red swirl, and another 1 ½ cups into a third bowl for the blue swirl.

Step 8: Add red food coloring to the first separated batter and mix until fully colored. Add blue food coloring to the other separated batter and mix as well.

Step 9: Using a 1/4-cup measuring cup, layer the batters in the prepared Bundt pan starting with plain batter, then red, then blue. Repeat the layering until all batter is used, alternating colors without stirring.

Step 10: Gently tap the pan a few times on the counter to level the batter without mixing the colors.

Step 11: Bake for 50 to 70 minutes, or until a wooden toothpick inserted in the center comes out clean.

Step 12: Allow the cake to cool in the pan on a wire rack for 15 minutes before inverting it onto the rack to cool completely.

Tips & Variations

For an extra smooth batter, sift the flour mixture twice before adding it to the wet ingredients.

Use gel food coloring to achieve more vibrant colors without altering the batter’s consistency.

If you don’t have buttermilk, substitute by mixing 1 cup of milk with 1 tablespoon of lemon juice or vinegar and letting it sit for 5 minutes.

For a different flavor twist, add a teaspoon of almond or lemon extract along with vanilla.

FAQs

Can I use a different pan instead of a Bundt pan?

Yes, you can use a 9×13-inch baking pan or two 9-inch round pans. Adjust the baking time accordingly, checking for doneness with a toothpick.

How do I prevent the colors from bleeding into each other?

Be sure to gently layer the batter without stirring after adding the colored batters. Tapping the pan lightly helps level the batter without blending the colors.