Lemon Shortbread Thumbprint Cookies

Dough

1. Cream the butter and sugar
2. Mix in the vanilla, lemon zest, and lemon juice
3. Add in the flour and mix, on low speed, just until a dough forms
4. Compact the dough, wrap in plastic, and refrigerate while making the jam

Jam

1. Combine all ingredients in a pot on the lowest heat until the berries are defrosted
2. Put a few spoons in the freezer
3. Bring the mixture to a boil
4. Cook the jam, stirring often, until the jam sets on the back on a cold spoon, about 20 minutes
5. Press the jam through a sieve to remove any seeds
6. Let the jam cool while shaping the cookies

Cookies

1. Roll the dough into small balls, about 1 tablespoon of dough per cookie
2. Press your thumb into each dough ball, trying to keep the walls of the pocket even in height
3. If any cracks form, try to smooth them over or compress the dough a little to fill them back up
4. Space the cookies out evenly on two baking sheets and refrigerate for another 30 minutes to help the cookies keep their shape
5. Preheat the oven to 350°
6. Fill each cookie with jam, being careful not to overflow the pockets
7. Bake until the cookies are just beginning to brown, about 13 minutes
8. Let cool, or even chill, before serving