Preheat oven to 400 degrees. Line a muffin pan with paper cups. This make 6 muffins.
In a large bowl, mix all of the dry ingredients: almond flour, rice flour, arrowroot, xanthum gum, baking powder, baking soda, salt, sugar and poppyseeds. Stir together and break up an lumps.
In a second small bowl, crack the egg. Whisk until it's foamy. Add olive oil, orange juice and milk and stir well. Pour wet ingredients into dry and add the zest. Stir with a spatula about 15 strokes until the dry ingredients are incorporated. Work quickly to put the batter into the prepared muffin pan. Sprinkle tops with sugar if you'd like.
Bake for 2 minutes at 400, then reduce heat to 375. Bake additional 25 minutes. Or until tops spring back with gently poked.