In a medium saucepan set over medium heat, add the blueberries, sugar, lemon juice and zest. Stir to combine and simmer until the berries start to burst. If necessary, use a potato masher to mash berries to help them release their juices. Remove from heat and set aside to cool to room temperature.

Preheat oven to 425° F. Line a baking sheet with parchment paper and set aside.

In a large bowl (see notes for food processor instructions), whisk together flour, 3 tablespoons sugar, baking powder and salt. Add cold butter and use a pastry cutter to blend butter into the dry ingredients until pea-sized butter pieces form. Work quickly so butter stays cold!

In a measuring cup, whisk together 1/2 cup half-and-half and egg. Pour egg mixture over the flour mixture. Use a silicone spatula or wooden spoon to combine ingredients. Mix until large clumps form.

Transfer biscuit dough to a floured work surface and knead a few times until the dough comes together in a ball (this step is important, but work quickly so the dough stays cold). Use your hands to press dough into a rectangle 9-inches by 5-inches. Dust a 3-inch biscuit cutter with flour and cut 6 round biscuits out of the dough. Rework remaining scraps and cut 2 more biscuits. Place biscuits 1-inch apart on prepared baking sheet. Brush biscuits with remaining tablespoon of half-and-half. Sprinkle with sugar.

Bake biscuits at 425° F for 12 to 14 minutes or until the edges are set. Allow biscuits to cool on the pan for 5 minutes before moving to a wire cooling rack.

In the bowl of a stand mixer fitted with a whisk attachment, combine heavy cream, sugar and vanilla. Turn mixer on low and mix for about 30 seconds until bubbles form. Slowly start turning the mixer up until it reaches medium-high. Beat until stiff peaks form and the whisk leaves a trail in the whipped cream, about 2 more minutes.

Cut biscuits in half (it's okay if they are still slightly warm). Layer with blueberries and whipped cream. Serve immediately.