Preheat oven to 375°F (190°C).
In a large mixing bowl, cream together butter and sugar until light and fluffy.
Beat in the egg.
In a separate mixing bowl, whisk together the flour, baking powder, and salt.
Gradually stir the flour mixture into the butter mixture, alternating with the milk, until a dough forms.
Roll the dough out on a floured surface and transfer to a 9-inch pie dish.
Prick the dough with a fork and sprinkle blueberries over the bottom.
In a separate mixing bowl, whisk together the heavy cream, sugar, egg, and vanilla extract until smooth.
Pour the cream mixture over the blueberries.
Bake for 40-45 minutes, or until the filling is set and the crust is golden brown.
Allow to cool before serving.