
Preheat oven to 350 F. Line 2 baking sheets with parchment paper.
In a large mixing bowl, mix together granulated sugar and lemon zest.
Add butter and brown sugar and mix on medium-high speed for about 3-4 minutes until light and fluffy. Add egg yolk, vanilla, and lemon juice.
Slowly mix in salt, baking powder, baking soda, and flour. Stop mixing when you still have some flour remnants.
Chop or break up frozen raspberries into little pieces and fold into the dough carefully.
Scoop the dough into large balls and place on lined baking sheet. Sprinkle with flaked salt.
Bake cookies for 12-15 minutes until golden brown around the edges.