Wash berries thoroughly and pat dry to remove excess water. Add fruits, jam, flour, sugar, vanilla extract and lemon juice to a mixing bowl and stir to combine well.
Unroll pie crust on a baking sheet lined with parchment paper. Place the filling in the center, make sure to leave about 2" along the circumference. Fold the crust over the fruit, pleating every couple of inches.
Brush the folded crust with eggwash, then sprinkle the coarse sugar on top of the crust. Bake for about 30 minutes. Start checking at the 20 minute mark, and watch for the fruit bubbling, and a golden brown crust.