Prepare the oven: Preheat your oven to 375 degrees Fahrenheit and line a baking sheet with parchment paper or a silicone mat.
Cut the biscuits: Remove the biscuits from the can and separate them along the perforations, then cut each biscuit into quarters with a knife or kitchen scissors to create bite-sized pieces.
Coat with butter: Place the melted butter in a shallow bowl and toss each piece through the melted butter until fully coated on all sides.
Apply cinnamon-sugar: In another shallow bowl, whisk together the sugar and cinnamon, then roll each butter-coated piece in the mixture until completely covered, shaking off any excess.
Arrange on baking sheet: Place the coated pieces on your prepared baking sheet in a single layer with about 1 inch of space between each piece.
Bake: Place the baking sheet in the preheated 375-degree oven and bake for 12 to 15 minutes, until the donut holes are light golden brown on the outside.
Cool slightly: Remove from the oven and let them cool on the baking sheet for 3 to 5 minutes so they firm up without becoming hard.
Transfer and serve: Move the donut holes to a serving plate or cooling rack while still warm, as they'll continue to set and develop a slightly crispy exterior.