Preheat the oven to 450°F. Place the sliced butter in a 9x9-inch glass baking dish and place it in the oven until melted (about 5-8 minutes). Carefully remove the pan from the oven.
In a large bowl, whisk together the flour, baking powder, salt, sugar, and black pepper.
Add the cooked sausage and shredded cheddar to the flour mixture and toss until evenly coated.
In a large measuring cup, whisk together the buttermilk, melted butter, and vanilla extract.
Pour the wet ingredients into the dry ingredients and stir just until combined. Do not overmix.
Spread the batter evenly over the melted butter in the baking dish. Using a butter knife, score the dough into 9 squares.
Bake for 25-35 minutes, or until the center is cooked through and the top is golden brown.
While the biscuits bake, whisk together the melted butter and maple syrup.
Brush the maple butter glaze generously over the hot biscuits immediately after removing them from the oven and sprinkle with maldon salt. Let cool for 5–10 minutes before serving.
