Ingredients:

  • 2.5 cups all-purpose flour
  • 1 cup granulated sugar
  • 1 tbsp baking powder
  • 0.5 tsp salt
  • 0.75 cup unsalted butter, softened
  • 0.5 cup vegetable oil
  • 3 large eggs, room temperature
  • 1 cup whole milk, room temperature
  • 0.5 cup sour cream, full fat
  • 1 tbsp pure vanilla extract
  • 1 cup unsalted butter, softened
  • 3 cups powdered sugar, sifted
  • 0.5 cup heavy whipping cream
  • 1 tsp pure vanilla extract
  • 1g salt

Instructions:

  1. Preheat the oven to 350°F (175°C). Grease a 9x13 inch baking pan and line the bottom with parchment paper.
  2. In a large bowl, whisk together the all-purpose flour, granulated sugar, baking powder, and salt until no clumps remain.
  3. Beat the softened butter and vegetable oil together until combined.
  4. Add the eggs one at a time, beating well after each addition.
  5. Stir in the pure vanilla extract and sour cream until the mixture is smooth and pale.
  6. Gradually add the dry ingredients to the wet mixture, alternating with the whole milk, starting and ending with the flour mixture.
  7. Mix on low speed just until the streaks of flour disappear; do not overmix.
  8. Pour the batter into the prepared pan and smooth the top.
  9. Bake for 30 minutes.