01 - Preheat the oven to 350°F and line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the flour, baking powder, and salt until evenly combined.
03 - In a large bowl, use an electric mixer to cream the softened butter, granulated sugar, and brown sugar on medium speed until light and fluffy, about 2-3 minutes.
04 - Beat in the eggs one at a time, mixing well after each addition, then stir in the vanilla extract.
05 - Gradually add the flour mixture to the creamed butter mixture, mixing on low speed just until the dough comes together. Do not overmix.
06 - Scoop 2-tablespoon portions of dough and flatten each into a disc in the palm of your hand. Place 1 teaspoon of strawberry jam in the center, then gently fold the dough over the filling, pinch the edges to seal, and roll into a smooth ball.
07 - Place the filled dough balls onto the prepared baking sheets, spacing them about 2 inches apart to allow for spreading.
08 - Bake for 11-13 minutes, until the edges are set and lightly golden but the centers still look slightly soft. Let the cookies rest on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.
09 - In a small bowl, whisk together the powdered sugar, milk, vanilla extract, and a drop of food coloring if desired, until smooth and drizzly. Spoon or drizzle the glaze over the completely cooled cookies and immediately top with sprinkles before the glaze sets.