Preheat oven to 350° F and line a baking sheet with parchment paper.
In a small bowl, whisk together flour, strawberry powder, milk powder, baking powder, baking soda, and salt. Set aside.
In a large mixing bowl, use an electric hand mixer to beat softened butter until creamy. Add sugar and cream together until fluffy, about 4 minutes.
Add in the egg and strawberry extract and mix until combined.
Add the flour mixture to the butter mixture and mix on low until almost combined. The dough will be crumbly with flour patches.
Add in the white chocolate chips and strawberry jam. Fold the mixture together until it forms a dough with some streaks of jam. Do not overmix.
Using a 4-tablespoon ice cream scoop, spoon out balls of cookie dough and place on your prepared baking sheet leaving 3-4-inches between each cookie.
Bake for 13-15 minutes or until edges are set and golden brown, but the middle is still soft.
Remove the cookies from the oven and let cool on the baking sheet for 10 minutes before removing to a wire rack to cool completely.