Preheat oven to 450 degrees F (230 degrees C). Combine baking mix, oats, milk, and hemp seeds in a bowl; stir until dough forms a ball. Fold in blueberries until evenly distributed. Drop heaping teaspoonfuls of dough onto an ungreased baking sheet. Bake in the preheated oven until golden brown, 8 to 10 minutes. Brush each biscuit with melted butter; sprinkle with brown sugar.