01 -
Preheat oven to 175°C. Line a baking sheet with parchment paper.
02 -
In a medium bowl, whisk together all-purpose flour, cocoa powder, baking soda, and salt until thoroughly combined.
03 -
In a large mixing bowl, beat the softened butter, granulated sugar, and brown sugar until light and fluffy.
04 -
Add the egg and vanilla extract to the creamed mixture and beat until fully incorporated.
05 -
Gradually mix the dry ingredient blend into the wet mixture, stirring until just combined.
06 -
If desired, add a few drops of purple food coloring to the dough and mix gently for an even hue.
07 -
Scoop tablespoons of dough and flatten each slightly. Place a small dollop of blueberry jam at the center, then enclose and shape into a ball.
08 -
Set dough balls on the prepared baking sheet, spacing evenly. Sprinkle the tops with granulated sugar.
09 -
Bake for 10 to 12 minutes, until edges are set but centers remain soft.
10 -
Allow cookies to set on the baking sheet for several minutes, then transfer to a wire rack to cool completely.