Place rack in the center of the oven, and preheat the oven to 425℉.
In a mixing bowl, whisk together the flour, baking powder, salt and sugar. Drizzle the cream over the dry ingredients and stir with a fork until the mixture forms a sticky ball of dough. Turn the dough out onto a floured surface. Knead 10 times with floured hands, adding a sprinkle of flour now and then if it's too sticky. Work in the blueberries at the end.
Pat the dough into a 9-inch round on a nonstick baking sheet. It's even better if you can line the baking sheet with parchment paper. Brush the top of the dough with the melted butter and sprinkle with sugar. Use a sharp knife to cut the round in half, then in half again, then cut each triangle in half to make 8 small wedges. Pull them apart slightly if you can.
Bake 15 to 20 minutes, or until the tops are golden brown and it's no longer gooey in the middle. Serve warm, or serve later at room temperature.