17/10/2025
Purple cake
Ingredients
For the cake:
All-purpose flour – 2 ½ cups (315g)
Cornstarch – 2 tbsp (helps soften the cake)
Baking powder – 2 tsp
Baking soda – ½ tsp
Salt – ½ tsp
Unsalted butter – 1 cup (225g), softened
Granulated sugar – 2 cups (400g)
Eggs – 4 large
Vegetable oil – ½ cup (120ml)
Buttermilk – 1 cup (240ml)
White vinegar – 1 tsp
Vanilla extract – 2 tsp
Purple gel food coloring – 2–3 tsp (adjust for shade)
For the purple buttercream frosting:
Unsalted butter – 1 ½ cups (340g), softened
Powdered sugar – 6 cups (720g), sifted
Heavy cream or milk – 3–4 tbsp
Vanilla extract – 2 tsp
Purple gel food coloring – 1–2 tsp (add gradually until desired shade)
Instructions
Preheat oven to 350°F (175°C). Grease and line four 8-inch round cake pans.
Whisk flour, cornstarch, baking powder, baking soda, and salt together. In a large bowl, beat butter and sugar until fluffy. Add eggs one by one, then mix in oil and vanilla. In another bowl, stir buttermilk with vinegar and purple food coloring until well blended.
Alternate adding dry ingredients and colored buttermilk mixture into the butter mixture, beginning and ending with dry ingredients. Mix just until smooth.
Divide batter evenly into the four prepared pans. Bake 22–28 minutes, or until a toothpick inserted in the center comes out clean. Cool cakes completely.
For the buttercream, beat butter until creamy. Gradually add powdered sugar, then vanilla. Add cream 1 tbsp at a time until smooth and spreadable. Mix in purple coloring until you reach the shade you like (lavender, deep violet, or pastel purple).
To assemble, place one cake layer on a stand, spread frosting evenly on top, then repeat with the next layers. Frost the outside of the cake smoothly, then decorate with swirls, rosettes, or ombre purple shading if desired.
