01 - Preheat oven to 350°F. Grease and line two 8-inch round cake pans with parchment paper.
02 - Whisk together flour, baking powder, baking soda, and salt in a medium bowl.
03 - Beat butter and sugar until light and fluffy. Add eggs one at a time, mixing well after each addition. Stir in vanilla extract.
04 - Add flour mixture in three parts, alternating with buttermilk. Begin and end with flour. Mix until just combined.
05 - Divide batter evenly between prepared pans. Bake for 25 to 30 minutes until a toothpick inserted in the center comes out clean. Cool in pans for 10 minutes, then transfer to wire racks to cool completely.
06 - Combine sliced strawberries with ¼ cup granulated sugar. Let stand for 20 minutes to macerate.
07 - Whip heavy cream with powdered sugar and vanilla extract until stiff peaks form.
08 - Place one cake layer on a serving plate. Spread half the whipped cream over the cake and top with half the strawberries including juices. Add second cake layer, spread remaining whipped cream, and decorate with remaining strawberries.
09 - Refrigerate for at least 30 minutes before serving for optimal texture.