Dice your fresh strawberries and lay them in a single layer on a piece of paper towel. This will pull out excess surface moisture from the berries.
Measure all of your dry ingredients into the bowl of your food processor. Pulse a few times to mix. Add cold butter cubes to the dry ingredients and pulse 5-6 times, or until most of the butter is in pea sized, or smaller, pieces. Pour into a mixing bowl, add the diced strawberries, and toss in.
Make a well in the center of the mixture and add the cold buttermilk. Gently bring the wet and dry together until you have a fairly uniform, loose dough. The flour won't look all mixed in and that's okay. It will come together.
Dump the dough out onto a lightly floured surface. Using your hands, gently bring it together into a rough square. With a bench scraper or knife, cut into four smaller squares. Stack the pieces of biscuit dough on top of each other. Smush it all down into a square again. Repeat this cutting and stacking procedure 2 more times.
Pat the dough into a rectangle at least ½ inch thick. Using a 2 or 3 inch biscuit or cookie cutter, cut out your biscuits. Gather your scraps as you go, gently re-form them together, and cut as many biscuits as you can. You should get 8 to 12 biscuits, depending on the size of your cutter.
Place your biscuits on a parchment paper lined small sheet pan. Put the sheet pan of biscuits in the freezer or refrigerator to chill while you preheat the oven to 450°F.
Remove biscuits from the freezer and brush the tops of the biscuits with an egg wash of one egg whiskied with one tablespoon of water or milk. Bake in a 425° oven for 18-20 minutes, or until golden brown.
In a small bowl, whisk together the powdered sugar, milk, and vanilla. Allow biscuits to cool for about 10 minutes, then drizzle generously with your glaze.