In a medium saucepan, combine the finely diced fresh strawberries and granulated sugar. Cook over medium heat for about 45 minutes, mashing the strawberries halfway through until the mixture thickens.

In a mixing bowl, beat the softened cream cheese, granulated sugar for the filling, and vanilla extract until smooth and creamy. Divide this mixture into 18 equal portions and freeze.

In a large mixing bowl, beat together the softened unsalted butter and granulated sugar until light and fluffy, about 3-4 minutes. Add the large egg and vanilla extract, mixing continuously.

Whisk together the all-purpose flour, baking powder, and salt in a separate bowl. Gradually mix with the butter mixture until just combined.

Divide the dough into four portions. Assemble cookies by layering dough, strawberry jam, and a frozen cheesecake disc before encasing the filling.

Shape each cookie into a flattened disc, ensuring the filling is fully wrapped, then place on a lined baking sheet.

Preheat oven to 350°F (175°C). Bake cookies for 11-12 minutes until edges are lightly golden. Cool on wire rack.