Prep the Dry Mix & Grate Frozen Butter: Preheat oven to 425°F (220°C). Line a large baking sheet with parchment paper. In a large mixing bowl, whisk together the flour, baking powder, baking soda, salt, and sugar. Coarsely grate 1 stick of frozen butter using the large holes of a box grater directly into the dry mixture. Gently toss with a fork to coat every butter ribbon with flour.

Hydrate & Laminate the Biscuit Dough: Pour in chilled buttermilk. Stir with a wooden spoon or fork just until a shaggy dough comes together (do not overmix). Turn out onto a lightly floured board and gently pat into a 0.75-inch thick rectangle. Fold the dough in half like a letter, turn 90 degrees, and gently flatten. Repeat this folding process 4 to 5 times—this creates dozens of visible flaky laminated layers!

Cut and Bake the Biscuits: Pat dough to a 1-inch thickness. Using a floured 2.5-inch round cutter, press straight down without twisting (twisting seals the edges and stops the rise!). Arrange cut biscuits touching each other on the baking sheet (touching sides helps them climb high). Brush tops lightly with buttermilk. Bake for 14 to 17 minutes until golden brown and towering. Brush tops with melted butter if desired.

Brown the Savory Breakfast Sausage: While biscuits bake, place a large cast-iron skillet over medium heat. Add the ground breakfast sausage, breaking it up with a wooden spoon into bite-sized crumbles. Cook for 6 to 8 minutes until browned and cooked through. Do not drain the savory pan drippings.

Build the Country Cream Gravy: Sprinkle 0.25 cup flour evenly over the sizzling sausage. Stir continuously for 2 minutes to cook out raw flour taste and coat every crumble. Slowly stream in the warm whole milk and heavy cream while whisking constantly to incorporate. Bring to a gentle simmer, cooking for 4 to 6 minutes until gravy thickens into a glossy, velvety consistency.

Season, Smother & Serve: Season the gravy generously with coarse black pepper, sea salt, and optional red pepper flakes. Split warm golden biscuits in half, transfer to warmed breakfast plates, and ladle piping hot sausage gravy generously over the tops. Garnish with chopped parsley and serve immediately!