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 until well combined.
03 - Beat softened butter and granulated sugar in a large bowl until light and fluffy, approximately 3-4 minutes.
04 - Add eggs one at a time, beating well after each addition. Mix in vanilla extract.
05 - Alternately add flour mixture and buttermilk to butter mixture, beginning and ending with flour. Mix until just incorporated.
06 - Divide batter evenly between prepared pans. Bake for 22-25 minutes until toothpick inserted in center comes out clean. Cool in pans for 10 minutes, then invert onto wire racks to cool completely.
07 - Combine sliced strawberries, granulated sugar, and lemon juice in a bowl. Let stand for at least 20 minutes, stirring occasionally to release juices.
08 - In a chilled bowl, whip heavy cream with powdered sugar and vanilla extract until stiff peaks form.
09 - Place first cake layer on serving plate. Spread with half the strawberry mixture and juices, then half the whipped cream. Add second cake layer. Top with remaining strawberries and whipped cream. Garnish with whole strawberries if desired.
10 - Refrigerate assembled cake for 1 hour before slicing to allow flavors to meld and structure to set.