For the Strawberry Jam:

1. Combine strawberries, granulated sugar, and lemon juice in a medium saucepan.
2. Heat over medium heat until berries break down and thicken, stirring occasionally.
3. Remove from heat and let cool completely.

For the White Cupcakes:

1. Preheat oven to 350°F and line a cupcake pan with 12 liners.
2. Sift together cake flour, baking powder, baking soda, and salt in a small bowl.
3. Cream butter and granulated sugar until fluffy, then add egg whites and vanilla.
4. Alternate adding buttermilk and dry ingredients to butter mixture, mixing until combined.
5. Fill cupcake liners with batter and bake for 16-18 minutes.
6. Let cupcakes cool completely.

For the Strawberry Cream Cheese Frosting:

1. Beat butter on high speed until pale and fluffy, then add cold cream cheese and mix until combined.
2. Gradually add powdered sugar and mix until smooth.
3. Pulse freeze dried strawberries in a food processor until finely ground, then add to frosting and mix until fluffy.

Assembling the Cupcakes:

1. Core cupcakes and fill each with strawberry jam.
2. Pipe frosting onto cupcakes and serve!