• In a bowl of the stand mixer, add the gluten free flour mix, almond flour, brown sugar, baking powder, baking soda, xanthan gum and salt. Mix with the paddle attachment for 30 seconds or until combined.
• Add the butter and mix for 45 seconds, scraping down the butter occasionally, until mixture looks crumbly.
• In a small bowl or measuring cup, mix the almond milk, sour cream, eggs, vanilla extract and apple cider vinegar until combined.
• With the mixer on low, slowly add the milk mixture to the dry ingredients. Mix until combined.
• Scrape down the bowl and turn the speed up to medium. Mix for 2 minutes.
• Gently fold the blackberries into the batter.
• Set batter aside to rest for 30 minutes.
• Toward the end of the rest time, preheat oven to 375 F. Make crumb topping. Spray each cup of a 12 cup muffin tin and 3 cups of another pan, with cooking spray.
• Portion the batter into the cups, filling each one to the top of the cup. Sprinkle with 2 teaspoons of crumb topping.
• Bake for 20-22 minutes or until toothpick test done.
• Cool in the pan on a wire rack for 10 minutes. Remove from pan.
• Serve warm or cool.

Crumb topping

• In a small bowl, mix almond flour, tapioca starch, coconut sugar, cinnamon and salt. Cut in the cold butter until mixture looks like crumbs.