In a large bowl sift together the dry ingredients; flour, baking powder, salt, and sugar. Using a pastry blender, cut in the butter and coat the pieces with the flour mixture (the mixture should look like coarse crumbs). Fold the blueberries into the batter (make sure not to mash the blueberries because the coloring will bleed into the dough). Make a well in the center of the blueberry dough mixture and pour in the heavy cream. Fold everything together just to incorporate; do not overwork the dough.