Sous Vide Vanilla Cake with Chocolate Frosting

Ingredients

• 2 cups (232.5 grams) cake flour
• 1 teaspoon (5 grams) baking powder
• 1/2 teaspoon (3 grams) salt
• 1 stick (113 grams) unsalted butter, at room temperature
• 1 cup (198 grams) granulated sugar
• 2 large eggs, at room temperature
• 1 teaspoon (5 mL) vanilla extract
• 1 cup (237 mL) buttermilk, at room temperature
• 4 tablespoons (56.5 grams) unsalted butter
• 3 tablespoons (16.5 grams) cocoa powder
• 1/4 cup (60 mL) whole milk
• 2 1/2 cups (284 grams) confectioners' sugar