To make this Lemon Pound Cake gluten free, replace the cake flour with a high-quality gluten-free flour blend that is designed for baking. Use a blend that includes xanthan gum, or add it if your blend does not already contain it. Also confirm that the lemon instant pudding mix and powdered sugar are certified gluten free, as some packaged products may contain hidden gluten or cross-contact risks. Because gluten-free cakes can be slightly more delicate, allow the cake to cool fully before removing it from the pan and glazing it.