Wash the blueberries and place on a clean towel to dry.
Line four muffin tin cups with paper liners.
Break the chocolate into small pieces and place the pieces in a microwave-safe glass measuring cup. Add the coconut oil.
Melt the chocolate in the microwave: run the microwave in 30 second increments, stirring the chocolate in-between and rotating the measuring cup. Finish when most of the chocolate is melted (mine took 1 minutes). Stir until smooth and fully melted.
Pour the melted chocolate into the paper liners, dividing it evenly. Divide the blueberries between the liners, allowing some to sink into the chocolate and some to remain on top.