Beat together the butter, salt, vanilla, and powdered sugar until smooth for the raspberry buttercream. Add the raspberry powder and milk and stir to combine.

Preheat oven to 350?F. Line two greased baking sheets with parchment paper.

In the bowl of a stand mixer, beat together the butter, salt, vanilla, lemon zest, and sugars until light and fluffy, about 4-5 minutes. Add the egg and beat for another 2 minutes.

Add the flour and baking soda, and beat until the dough comes together in a ball.

Portion the cookies onto the prepared cookie sheets (3 tablespoons for every cookie). Roll the scoops between your hands to make a ball. Flour the back of a ? cup measuring cup and press down to flatten it in the center.

Bake the cookies for 12 minutes, until just golden on the bottom. Let cool before frosting.

Dollop 1 tablespoon of buttercream per cookie and spread it around the top. Decorate as desired.