Preheat oven to 350 degrees and set out eggs to bring to room temperature.
Line a muffin tin with paper cups and set aside.
Make The Streusel:
Add the almond flour and whole pecans to the bowl of a food processor fitted with the "S" blade. Process until the mixture resembles sand.
Add the remaining ingredients and process until well combined. Set aside.
Combine the blueberries with 1 ½ Tbsp. of arrowroot flour in a small bowl and set that aside also.
For the Cake:
Whisk together the almond flour, remaining ¾ C of arrowroot, salt, and baking powder in a large bowl.
If the eggs are still cold, run under warm water. Then, whisk together the eggs, honey, vanilla, coconut oil, and lemon juice, adding the coconut oil last to keep it from solidifying.
Pour the wet ingredients into the dry and beat on medium-high until the batter is smooth.
Stir in the blueberries.
Fill each muffin cup almost full, then liberally sprinkle the streusel topping onto each muffin.
Bake 16 - 20 minutes (my oven seems to cook fast) or until nicely browned.