Preheat oven to 325 degrees F (165 degrees C). Line two 12-cup muffin tins with paper liners.
Whisk flour, baking powder, and salt together in a bowl.
Combine butter and 1 cup sugar in a bowl; beat with an electric mixer until creamy. Beat in eggs one at a time. Mix in vanilla extract. Add the flour mixture alternately with milk, beating batter very briefly after each addition.
Pour batter evenly into the lined cups.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 20 minutes. Cool in the tins for 5 minutes. Transfer to a wire rack to cool completely.
Combine cream cheese, 1/3 cup sugar, heavy cream, and strawberry jam in a bowl; beat with an electric mixer until creamy.
Slice off the sides of 8 strawberries to remove seeds. Mash strawberries in a small bowl with a fork. Beat into the cream cheese mixture until fully incorporated.
Cut a small hole in the center of each cooled cupcake; scoop out about 1/2 inch of cake. Fill each gap with a spoonful of the cream cheese frosting.
Top each cupcake with a swirl of whipped cream. Place 1 strawberry slice in the center of each cupcake.