Wash the berries. Hull and slice the strawberries. Place half the berries into a bowl with the sugar. Mash them with a potato masher or the back of a fork. Toss in the remaining berries and set them aside to macerate and release their juices. About 30 minutes.

Preheat the oven to 375 deg F. Line a baking sheet with parchment paper and set aside.

In a food processor, pulse together the flour, brown sugar, baking powder, and salt. About 15 pulses just to break down the brown sugar.

Slice the butter into 1/2 inch cubes and add to the food processor. Pulse 10 times until the mixture looks like coarse meal. Transfer to a large bowl.

In a small bowl, whisk the egg and sour cream together. Stir into the flour mixture until a thick dough starts to form. Use your hands to kneed the dough into a ball. There should be no flour visible.

Use an ice cream scooper to measure out six rounds placing each one on the prepared baking sheet. Brush the tops with melted butter and sprinkle on the sugar.

Bake for 25 - 30 minutes. The tops of the shortcakes should be golden brown. Remove from the oven and cool for 10 minutes.

In a stand-up mixer or a large bowl, combine the heavy cream, sour cream, and light brown sugar. Whisk on medium and increase to high whipping until stiff peaks form.

When ready to serve, slice the shortcakes in half. Spoon over the mixed berries, add the whipped cream, and top with the shortcake top.