To make this recipe gluten free, replace the all-purpose flour in both the cake and crumb topping with a high-quality 1:1 gluten-free baking flour blend that includes xanthan gum. Also confirm that the baking powder, confectioners’ sugar, pumpkin puree, maple syrup, and any coffee creamer used are certified gluten free, as ingredients and manufacturing practices can vary by brand. The texture may be slightly more delicate than the original version, so allow the cake to cool a bit before slicing for cleaner pieces.