Key lime cake

Ingredients:

Cake

• 220g unsalted butter, softened, plus extra for greasing the pan
• 2.5 cups premium flour
• 0.5 tsp baking powder
• 0.5 tsp of soda
• 0.5 tsp fine salt
• 1 and 1/4 cups of sour milk or kefir, shake well
• 2 tsp vanilla extract
• 2 cups granulated sugar
• 3 large eggs, lightly beaten
• 1 packet (85 g) of lime jelly mix

Topping

• 2 cups chilled heavy cream
• 1 tbsp. granulated sugar
• 2 tsp vanilla extract
• Green decorative sugar, for sprinkling

Preparation:

1. Position a rack in the lower third of the oven and preheat to 350°F (175°C). Grease the bottom and sides of a 9 x 13-inch (22 x 32 cm) springform pan. In a medium bowl, whisk together the flour, baking powder, baking soda, and salt; set aside. In a measuring cup with a spout, combine the buttermilk and vanilla extract; set aside.
2. Beat the butter and sugar with a mixer on medium speed until light and fluffy, about 5 minutes, scraping down the sides of the bowl as needed. While continuing to beat, gradually add the eggs and beat until fully incorporated. Reduce the mixer speed to low and add a third of the flour mixture, then half of the milk mixture, then half of the remaining flour, the remaining milk mixture, and then the remaining flour. Scrape down the sides of the bowl and knead until smooth.
3. Pour the batter into the prepared pan. Bake until golden brown and a toothpick inserted into the center comes out clean, about 30 minutes, rotating the pan halfway through baking. Let cool in the pan for 30 minutes. Then, using a large fork, poke holes in the cake 2 inches apart.
4. In a medium bowl, pour 1 cup of boiling water over the jelly mixture and stir until completely dissolved, about 2 minutes. Add 0.5 cups of cold water. Pour the mixture evenly over the cooled cake layer. Refrigerate for 2 hours. Place a large bowl (for whipping cream) in the refrigerator.
5. Remove the cake from the refrigerator. Whip the cream with sugar and vanilla in a chilled bowl. Spoon the whipped cream over the cake and sprinkle with decorative sugar. Slice and serve.