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. Set aside.
03 - In a large bowl, beat softened butter and granulated sugar until light and fluffy, approximately 3-4 minutes.
04 - Beat in eggs one at a time, fully incorporating each before adding the next. Stir in vanilla extract.
05 - Alternately add flour mixture and buttermilk to butter mixture, beginning and ending with flour. Mix until just combined, being careful not to overmix.
06 - Divide batter evenly between prepared pans. Bake for 22-25 minutes until a 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 and create a syrupy consistency.
08 - In a chilled bowl, whip heavy cream with powdered sugar and vanilla extract until stiff peaks form, approximately 3-4 minutes.
09 - Place one cooled cake layer on serving plate. Spread half the strawberry filling with juices over cake, then top with half the whipped cream. Add second cake layer. Repeat with remaining strawberries and cream. Garnish with whole strawberries if desired.
10 - Refrigerate assembled cake for at least 1 hour to allow flavors to meld and cake to set before slicing.