01 - Preheat oven to 350°F. Line a 9x13-inch baking pan with parchment paper and lightly grease with butter or cooking spray.
02 - In a medium bowl, whisk together flour, baking powder, baking soda, and salt until well blended.
03 - In a large bowl, beat softened butter and granulated sugar with an electric mixer on medium speed until light and fluffy, approximately 3 minutes. Add eggs one at a time, beating well after each addition. Mix in vanilla extract.
04 - Add dry ingredients to butter mixture in three alternating additions with milk, beginning and ending with flour mixture. Mix on low speed just until incorporated, avoiding overmixing.
05 - Spread batter evenly into prepared pan. Bake for 22 to 25 minutes until a wooden toothpick inserted in center comes out clean. Cool completely in pan on wire rack, approximately 1 hour.
06 - While cake cools, combine sliced strawberries, granulated sugar, and lemon juice in a bowl. Toss gently to coat. Let stand at room temperature for 20 minutes, stirring occasionally, until strawberries release their juices.
07 - In a chilled bowl, beat cold heavy cream, powdered sugar, and vanilla extract with an electric mixer on medium-high speed until medium-stiff peaks form, approximately 3 to 4 minutes.
08 - Once cake is completely cool, spread whipped cream evenly over surface. Spoon macerated strawberries and their accumulated juices over whipped cream layer. Serve immediately or refrigerate until ready to serve.