Prepare the Cake Layers: Preheat your oven to 350°F (175°C). Grease and line two 8-inch round cake pans. In a bowl, whisk together flour, baking powder, and salt. In another bowl, cream butter and sugar until light and fluffy. Add eggs one at a time, then mix in vanilla. Gradually add dry ingredients, alternating with milk, until smooth. Divide batter evenly between pans and bake for 25–30 minutes, or until a toothpick comes out clean. Cool completely.
Make the Strawberry Filling: Combine sliced strawberries, sugar, and lemon juice in a saucepan. Cook over medium heat for 5–7 minutes until berries release their juices and soften. If you prefer a thicker filling, stir in cornstarch mixed with 1 tsp water and simmer for another minute. Let cool completely.
Whip the Cream: In a chilled bowl, beat heavy cream, powdered sugar, and vanilla extract until stiff peaks form. Keep refrigerated until assembly.
Assemble the Cake: Place one cake layer on a serving plate. Spread a layer of whipped cream and spoon strawberry filling evenly over it. Place the second cake layer on top. Frost the entire cake with whipped cream and decorate with fresh strawberries.