Preheat the oven to 375℉. Spray a 12-count muffin pan with nonstick spray, or line with cupcake liners and lightly spray with oil. Set aside.
Place pistachios in a blender or food processor and finely chop. Set aside.
Combine orange juice, coconut oil, orange zest, vanilla, and ground flaxseeds in a bowl.
Mix gluten-free flour, almond flour, sugar, baking powder, salt, and pistachio in a large bowl.
Mix the orange juice mixture with the dry ingredients into a smooth batter.
Spoon the batter into the prepared muffin pan, filling them.
Bake for 25-30 minutes or until a fork inserted into the center comes out clean. Enjoy!