Preheat oven to 350 degrees.
Line a baking sheet with parchment paper.
In a large bowl combine strawberries, blueberries and lemon juice. Set aside.
In a small bowl whisk together 3 Tbsp. flour, 1/3 cup granulated sugar, cinnamon and nutmeg.
Pour mixture over berries and toss until evenly coated.
Place mixture in a 9 inch deep dish pie plate and place on prepared baking sheet.
In a medium bowl whisk together the remaining one cup flour, 3 Tbsp. sugar and baking powder.
Cut in the cold, cubed butter with a pastry blender, until the mixture resembles coarse crumbs.
Add the egg, milk and vanilla to the flour mixture until just combined. Spoon over the berries by heaping tablespoonfuls. Sprinkle with turbinado sugar.
Bake for 35 minutes until biscuits are golden brown and filling is bubbly.
Cool for 10 minutes before serving. Serve with fresh whipped cream or vanilla ice cream if desired.