In a small food processor, pulse the freeze dried strawberries until they are a fine dust. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat together the butter and sugar on medium speed for 4 minutes.
Scrape down the sides of the bowl, and beat in the egg until well combined. Add in the egg yolk and vanilla, beating until well combined.
Scrape down the sides of the bowl. Add in the flour, baking powder, salt, and baking soda. Beat just until no flour streaks remain.
Divide the dough into 3 equal portions (~300g each).
Put one portion of the dough into the stand mixer. Add in the freeze-dried strawberries and mix until just combined, being careful to not over-mix. Transfer to a bowl.
Wipe down the inside of the bowl, and add another portion of the dough to the stand mixer. Add in the cocoa powder, and mix until just combined.
Use a 1.5 tbsp. cookie scoop to portion out each section of the cookie dough one dough at a time. Wipe down the cookie scoop between flavors for cleaner distinctions between flavors, if desired.
In your hands, stack one ball of each flavor on top of each other, slightly push down, and roll to form a large cookie dough ball. Repeat until you have used up all of the dough.
Cover the dough and chill in the fridge for at least 30 minutes, up to overnight.
Preheat the oven to 350°F / 175°C. Line a baking sheet with parchment paper or a silicone baking mat. Place the cookies on the pan, leaving at least 2 inches between each cookie to allow room for spreading. Bake for 18 minutes, or until the edges begin to brown. Leave cookies on the hot cookie sheet for an additional 5 minutes before transferring to a wire rack to cool.
Top with additional sugar if desired. Serve, and enjoy!