In a medium mixing bowl, whisk flour, freeze-dried strawberry powder, baking powder, baking soda and salt together. Set aside.
In a separate mixing bowl, with an electric mixer, beat the butter, cream cheese and sugar together until light and fluffy, about 3 - 4 minutes.
Add egg and vanilla, then beat until fully combined.
Add flour mixture and beat just until combined. Using a rubber spatula, scrape the bottom and sides of the bowl, then fold the cookie dough a few times to incorporate everything fully.
Using a small cookie scoop, portion dough out into 30 balls onto a parchment-lined baking sheet. Cover with plastic wrap and refrigerate for 30 minutes.
Preheat oven to 350°F / 325°F with convection / 180°C / Gas mark 4.
Place 12 cookie dough balls on parchment-lined baking sheet and bake for 12 - 14 minutes. Cookies should barely take on color - do not bake until brown. Rotate pans halfway through baking time to ensure even baking. Repeat until all the dough has been used.
Let cookies cool on sheet pan for 10 minutes before transferring to a cooling rack to cool completely.