Preheat the oven to 180°C (356°F).
Put blueberries and cocoa powder in a bowl.
Add almond flour, baking powder, and salt, and mix well.
Add egg, unsweetened yogurt, and vanilla extract, then knead into a dough.
Melt coconut oil and mix it well into the dough.
Shape the dough into balls and place them on a baking sheet.
Bake in the oven at 180°C (356°F) for 12–15 minutes.
Let cool before serving.