Preheat the oven to 400°F degrees.
Place baking paper on an oven tray.
Whisk the flour, baking powder, salt, and sugar in a bowl.
Grate the frozen butter over the dry ingredients. With your fingers or a pastry cutter, gently knead butter into the flour mixture. The mixture should resemble coarse crumbs. Be careful not to overmix, and don't use your palms.
Add the buttermilk, and with a spatula, bring the dough together. Act quickly and form a ball.
Flour a surface. Roll the dough and form a rectangular shape. Take the blueberries out of the freezer, place them on the dough, and lightly press with your palms for them to merge into the dough. Be careful not to crush the blueberries.
Pat the dough. It should be about 1-inch thick. Use a biscuit cutter to cut out. Reroll the remaining dough and repeat the process.
Transfer the biscuits onto the tray.
Bake in the oven for about 15 minutes. When cooked, they should appear golden brown in color. Check frequently after 12 minutes.
When biscuits are baked, take the tray out of the oven and let them rest for five minutes at room temperature.
During the resting period, prepare the glaze. Put the confectioner's sugar in a mixing bowl. Add the salt and whisk. Make a well at the center and pour the half-and-half and vanilla extract. With a hand whisk, stir until you get a smooth, thick, runny texture.
Drizzle the vanilla glaze over the warm biscuits.
Serve the Bo-Berry biscuits with fresh blueberries on the side.