Preheat your oven to 425°F. Line the muffin tins with muffin liners, alternating to fill only 6 in each tray that holds 12. Spray liners with non-stick spray.
In a large bowl, mix together sweeteners and melted butter to dissolve. Once well mixed, add in yogurt, and vanilla extract. Continue mixing to combine completely, then mix in eggs one at a time. The batter may separate a bit, but it will be fine once all ingredients are mixed in.
Sift all of your dry ingredients (almond flour, baking powder, baking soda, salt, cinnamon, and xanthan gum) and then fold into the wet ingredients until well combined.
In a small bowl, combine most of the blueberries with 1 tablespoon of coconut flour. Toss to combine. Set the remaining blueberries aside to top the muffins. Gently fold in the blueberries with a rubber spatula, and mix until just combined.
Use a large cookie scoop to fill up the muffin liners most of the way with batter. Bake for 5 minutes at 425°F, then, without opening the oven door, reduce the heat to 350°F and bake for an additional 15-18 minutes until golden brown and a toothpick comes out clean.
Cool for 5 minutes in the muffin tin, then transfer immediately to a cooling rack to completely. Enjoy!
Store at room temperature in an airtight container for up to 3 days. After 3 days, transfer to the fridge for another 3-4 days. To freeze, allow muffins to cool completely, then freeze on a baking sheet for an hour before transferring them to a freezer-safe bag. They will keep for up to 6 months. To thaw, allow to sit out at room temperature for an hour or so or reheat in the microwave.