Ingredients:

3 TBSP flax seeds

1 TBSP, plus 2/3 cup coconut sugar

2-3 TBSP lemon zest

1 TBSP lemon juice

1 cup (4 oz.) arrowroot flour

3 large eggs

1/2 cup water

3 TBSP coconut oil (melted and cooled to room temp.)

1 TBSP vanilla extract

1 tsp sea salt

3 cups (9 oz.) almond flour

3 TBSP coconut flour

1 1/2 tsp baking soda

1/4 tsp cream of tartar

1/8 tsp ground nutmeg

1 1/2 cup (7.5 oz.) fresh or thawed frozen blueberries

Instructions:

(If using frozen blueberries, rinse them gently after thawing to remove excess juice and spread them out on paper towels to absorb excess moisture before using.)

1. Adjust oven rack to middle position and heat oven to 325 deg. Grease 12-cup muffin tin. Combine flax seeds, 1 tablespoon sugar, and lemon zest in a bowl; set aside.
2. Using stand mixer fitted with whisk (or electric hand mixer), whip arrowroot flour, eggs, water, melted oil, vanilla, salt, remaining 2/3 cup sugar, and lemon juice on medium speed until thoroughly combined, about 1 minute. Let mixture rest in mixer bowl for 30 minutes.
3. Whisk almond flour, coconut flour, baking soda, cream of tartar, and nutmeg together in bowl. With mixer set to low speed, add almond flour mixture to liquid mixture and mix until incorporated, about 30 seconds. Increase speed to high and whip batter until light and fluffy, about 1 minute, scraping down sides of the bowl as needed. Using rubber spatula, fold in blueberries.
4. Divide batter evenly among prepared muffin cups (cups will be filled to the top) and sprinkle with reserved flax seed mixture. Bake until muffins are golden brown and toothpick inserted in center comes out clean, about 22-25 minutes, rotating muffin tin halfway through baking.
5. Let muffins cool in muffin tin for 10 minutes, then transfer to wire rack and let cool for 15 minutes before serving. (Muffins are best eaten warm on the day they are made, but they can be cooled, immediately transferred to zipper-lock bag, and stored at room temperature for up to 1 day. To serve, warm in 300 degree oven for 10 minutes. Muffins can also be wrapped individually in plastic wrap, transferred to zipper-lock bag, and frozen for up to 3 weeks.