To adapt this raspberry muffins recipe for a gluten-free diet, substitute the all-purpose flour with a 1:1 gluten-free flour blend that includes xanthan gum (such as Bob’s Red Mill or King Arthur’s Gluten-Free All-Purpose). Ensure the baking powder is certified gluten-free, as some brands may contain gluten-based starches. Mix gently and avoid overworking the batter, as gluten-free flour behaves differently. The texture may be slightly more delicate but equally delicious.