Preheat oven to 400° & cut your cold butter into cubes.
To Make the Biscuits: In large bowl or food processor, add 3 & ¼ cups flour, 2tbs baking powder, 1tsp salt ⅓ cup sugar & 12tbs cold, chopped up butter.. Pulse until the butter is in varying sized chunks, mostly pea sized. Or you can use your hands to break up the butter in the flour without food processor. Next, pour in cold buttermilk. Pulse again until dough is shaggy. Or mix with wooden spoon or spatula.
Bake Biscuits: Turn "shaggy" dough out onto the table and try to mix in any remaining dry flour. Press out the dough roughly into a square and cut in fours. Pile all four squares on top of each other & repeat a second time. Finally, roll out the dough with your rolling pin to cut your biscuits. Cut as many as you can using a biscuit cutter or circle cookie cutter. You can also roughly cut into squares with a knife. Place biscuits all up against each other in a cast iron or in center of baking sheet. Baste tops of biscuits with remaining 2tbs buttermilk & sprinkle with coarse sugar. Bake 30 minutes or until risen and golden brown.
Strawberry Shortcakes: In a large bowl, add 1 cup strawberry slices & ⅓ cup sugar. Mash up with the back of a fork as best as you can. Add the remaining 4 cups strawberry slices & toss. Let sit while biscuits bake or overnight in refrigerator.
Whip Cream: Whip ¾ cup heavy cream to soft peaks with whisk or hand mixer. Add powdered sugar & vanilla and lightly whisk to incorporate.
Assemble: Pull apart warm biscuits & layer with strawberries & whipped cream. You can reheat biscuits in microwave for a few seconds or oven.