Pre-heat oven to 375 degrees and line a baking sheet with parchment paper or a Silpat.
In a large bowl, whisk together the flour, baking powder, sugar, cream of tartar, salt, and pepper.
Work the butter into the flour using a pastry blender or your hands, until it resembles coarse meal. Blend in shredded cheddar cheese, pepperoni, and basil.
Add buttermilk and pizza sauce to the dry ingredients and stir until just combined, taking care not to over-mix. Dough will be wet.
Place dough on a lightly floured surface and knead just until it comes together. If dough is too sticky, you can add a bit more flour. Pat dough into a round about ¾-inch thick. Using a biscuit cutter with a roughly 2 ¾-inch diameter (you can also use a drinking glass, circle cookie cutter, etc.), cut rounds out of dough.
Place biscuits about 2 inches apart on prepared baking sheet and re-work dough to continue cutting out biscuits.
Bake biscuits for 20-24 minutes, until they’re just turning golden on top.
Serve warm or cool on baking racks before serving.