To make this Old-Fashioned Chocolate Gravy gluten-free, substitute the all-purpose flour with a 1:1 gluten-free baking flour blend that contains xanthan gum for thickening. Ensure that your cocoa powder and vanilla extract are certified gluten-free, as some brands may contain trace gluten. The result will be equally smooth, rich, and flavorful, maintaining the same classic Southern charm while accommodating a gluten-free diet.