Preheat oven to 350°F. Line baking sheets with parchment paper.
In a large bowl, beat the butter and sugar together for 2–3 minutes until light and fluffy.
Add the eggs one at a time, mixing well after each addition. Mix in the strawberry extract, vanilla extract, and food coloring until fully combined.
In a separate bowl, whisk together the flour, sifted freeze-dried strawberry powder, cornstarch, baking powder, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing just until a thick dough forms. The dough should be soft but not sticky. If it feels too soft, mix in 1–2 tablespoons of flour.
Divide the dough into 12 large portions (about ¼ cup each). Roll into balls and gently flatten into thick discs.
Chill the dough for 20–30 minutes to help prevent spreading.
Bake for 11–13 minutes, until the edges are set and the centers still look slightly underbaked. The tops should remain pale and not turn golden.
Allow the cookies to cool on the baking sheet for 10 minutes, then transfer to a cooling rack and let them cool completely.
In a separate bowl, beat the butter until smooth. Add powdered sugar, vanilla extract, and 1 tablespoon of heavy cream. Beat until thick and fluffy, adding more cream only if needed. Mix in almond extract if using.
Once the cookies are completely cooled, pipe or spread frosting onto each cookie and finish with rainbow sprinkles.