Classic Yellow Layer Cake with Chocolate Buttercream

Thermomix recipe: Classic Yellow Layer Cake with Chocolate Buttercream. Ready in 58 minutes. Serves 12. Step-by-step Thermomix instructions on Chef Amai.

Ingredients

• 285 g cake flour
• 2.5 tsp baking powder
• 0.25 tsp baking soda
• 0.5 tsp salt (for cake)
• 170 g unsalted butter, softened
• 350 g granulated sugar
• 80 ml vegetable oil
• 4 large egg yolks, room temperature
• 1 tbsp pure vanilla extract (for cake)
• 240 ml buttermilk, room temperature
• 2 large egg whites, room temperature
• 0.125 tsp cream of tartar
• 282 g unsalted butter, softened (for frosting)
• 420 g confectioners' sugar
• 65 g unsweetened cocoa powder
• 45-75 ml heavy cream
• 1 tsp pure vanilla extract (for frosting)
• 0.25 tsp salt (for frosting)
• Sprinkles (optional, for decoration)

Instructions

1. Preheat the oven to 177°C (350°F). Grease two 23 cm (9-inch) round cake pans, line with parchment paper rounds, then grease the parchment paper. Set aside.
2. Add 285 g cake flour, 2.5 tsp baking powder, 0.25 tsp baking soda, and 0.5 tsp salt to the Thermomix bowl. Mix 10 sec / Speed 4. Transfer to a separate bowl and set aside. Clean and thoroughly dry the Thermomix bowl.
3. Insert the butterfly whisk. Add 170 g softened unsalted butter, 350 g granulated sugar, and 80 ml vegetable oil to the clean Thermomix bowl. Cream 3 min / Speed 3.5.
4. Scrape down the sides of the Thermomix bowl. Add 4 large egg yolks, one at a time, through the lid opening every 30 seconds while mixing 2 min / Speed 3.5. Add 1 tbsp pure vanilla extract and mix 15 sec / Speed 3.5.
5. Remove the butterfly whisk. Add 240 ml buttermilk to the Thermomix bowl. Add one-third of the reserved dry ingredients and mix 10 sec / Speed 3 / Reverse. Scrape down the sides.
6. Add another one-third of the reserved dry ingredients and mix 10 sec / Speed 3 / Reverse. Scrape down the sides.
7. Add the remaining dry ingredients and mix 15 sec / Speed 3 / Reverse, or until just combined. The batter will be thick. Transfer the batter to a large mixing bowl and set aside.
8. Clean and thoroughly dry the Thermomix bowl and butterfly whisk. Insert the butterfly whisk. Add 2 large egg whites and 0.125 tsp cream of tartar to the Thermomix bowl. Whip 3 min / Speed 3.5, or until medium-stiff peaks form.
9. Gently fold the whipped egg whites into the cake batter in the large mixing bowl using a spatula, being careful not to deflate the mixture. Divide the batter evenly between the two prepared cake pans.
10. Bake for 27–31 minutes, or until a toothpick inserted in the center of the cakes comes out clean. Cool the cakes in the pans set on a cooling rack for 1 hour. Run a knife around the edges to loosen the sides, remove the cakes from the pans, peel off the parchment, and place on the rack to finish cooling completely.
11. For the Chocolate Buttercream: Clean the Thermomix bowl. Insert the butterfly whisk. Add 282 g softened unsalted butter to the Thermomix bowl. Cream 2 min / Speed 3.5.
12. Add 420 g confectioners' sugar, 65 g unsweetened cocoa powder, 45 ml heavy cream, 0.25 tsp salt, and 1 tsp pure vanilla extract. Mix 30 sec / Speed 2, then increase to 1 min / Speed 3.5. Do not over-whip.
13. Check the frosting consistency. If too thick, add 1-2 tbsp (15-30 ml) more heavy cream and mix 10 sec / Speed 3.5. If too thin, add 30 g more confectioners' sugar and mix 10 sec / Speed 3.5.
14. Once cakes are completely cool, level the tops with a serrated knife if desired. Place one cake layer on your serving plate. Spread about 180-240 g of frosting evenly on top. Top with the second cake layer and spread a thin layer of buttercream over the top and sides for a crumb coat. Refrigerate for 20 minutes until set.
15. Finish by spreading the remaining buttercream over the top and sides of the cake. Decorate with sprinkles, if desired. For neat slices, refrigerate the cake for 30-60 minutes before slicing.

View this recipe on Chef Amai — convert any recipe to Thermomix format at chefamai.com.