
Preheat the oven to 350°F. Grease two 8-inch round cake pans, line the bottoms with parchment paper, and lightly flour the sides.

In a large mixing bowl or stand mixer fitted with the paddle attachment, beat the softened butter and brown sugar until pale and fluffy, about 2 minutes. Add the eggs one at a time, mixing well after each addition, then mix in 2 tsp vanilla extract and the melted chocolate chips.



In a separate bowl, whisk together the flour, cornstarch, baking powder, baking soda, and salt. Add the dry ingredients to the butter mixture in stages, alternating with the sour cream, water, and milk. Mix just until the batter is smooth and combined; do not overmix.



Divide the batter evenly between the prepared pans and smooth the tops. Bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs.



Let the cakes cool in the pans for 10 minutes, then turn them out onto a wire rack to cool completely. For the frosting, chill a clean mixing bowl for 15 minutes, then whip the heavy cream until soft peaks form. Add the remaining 1/2 tsp vanilla extract and the confectioners' sugar gradually, then continue whipping until fluffy, spreadable peaks form.



Slice each cooled cake layer horizontally to make 4 thin layers. Place one layer on a serving plate, spread with whipped cream, and repeat with the remaining layers. Frost the top with more whipped cream, chill briefly to set, then slice and serve with strawberries if desired.

