To make this Reese's Peanut Butter Cup Pie gluten-free. Ensure that all ingredients used are certified gluten-free. Most semi-sweet chocolate bars. And peanut butter. Are naturally gluten-free. But it's always best to check the labels. Additionally, you can use gluten-free powdered sugar. With these simple adjustments. You can enjoy this indulgent pie. Without any gluten-related concerns. Making it perfect. For those with gluten sensitivities. Or celiac disease.