Preheat oven to 425°F.
Line a baking sheet with parchment paper.
In a large bowl, mix the flour, baking powder, sugar, and salt. Add the butter and use your fingers to smush the butter into the flour mixture until the pieces are pea-sized. Work quickly so that the butter doesn't melt.
Add in the buttermilk and cheddar and mix with a rubber spatula or wooden spoon just until combined. The dough will be thick and sticky. Don’t over-mix.
Scoop the dough into roughly 8 equal mounds, about 1/3 cup each, and place spaced apart on the parchment-lined baking sheet.
Bake until lightly golden brown on top and they bounce back when lightly pressed, 20 to 22 minutes. Serve warm.