Preheat the Oven: Begin by preheating your oven to 425°F (220°C). Line a baking sheet with parchment paper to ensure your biscuits don’t stick.

Prepare the Dry Ingredients: In a large mixing bowl, whisk together the flour, baking powder, baking soda, and salt. This ensures that your leavening agents are evenly distributed throughout the flour.

Cut in the Butter: Add the cold, cubed butter to the flour mixture. Using a pastry cutter or fork, cut the butter into the flour until the mixture resembles coarse crumbs. The butter pieces should be about the size of peas.

Add the Sourdough Discard: Pour the sourdough discard into the dry ingredients. Stir gently to combine. The mixture will start to come together but remain a bit crumbly.

Incorporate the Milk: Gradually add the cold milk to the mixture, stirring just until the dough comes together. Be careful not to overmix, as this can lead to tough biscuits.

Roll Out the Dough: Turn the dough out onto a lightly floured surface. Using a rolling pin, roll the dough to about 1/2-inch thickness. For fluffier biscuits, you can roll them slightly thicker.

Cut the Biscuits: Using a biscuit cutter (or the rim of a glass), cut out biscuits from the dough. Press straight down without twisting to ensure the biscuits rise evenly. Re-roll the scraps as necessary.

Bake: Place the biscuits on the prepared baking sheet, spacing them about 1 inch apart. Bake in the preheated oven for 12-15 minutes, or until the tops are golden brown.

Serve: Remove from the oven and allow the biscuits to cool slightly before serving. Enjoy them warm with your favorite toppings.