Preheat oven to 350°F/175 C. Line a baking tray with parchment.

In a large bowl, combine flour, powdered sugar, salt, and cornstarch.

Stir to distribute everything evenly and break up any lumps of powdered sugar.

Add in the lemon zest and stir.

Drizzle in 10 tbsp/150ml of coconut oil. Stir to combine. If the dough is too crumbly, add an additional 1 tbsp/15ml coconut oil.

Allow to sit for 5 minutes for the oil to cool slightly if it was very warm otherwise the mixture won’t hold its shape.

Scoop barely heaping tablespoons of mixture. Roll into balls and place on the lined baking sheet with 2”/5cm between them.

Press your thumb or the back of a teaspoon measure into each ball to create a deep well. Reform any cracks that are formed.

Fill each well with a scant 1 tsp/5ml of blueberry jam (or just enough to fill the well and not be heaping (it will leak when baked if over filled).

Bake for 13-15 minutes until the bottom edge is just barely golden brown.

Allow to cool on the pan for 5 minutes before transferring to a cooling rack.