Preheat your oven to 350* and line your 12 muffin tin cups with parchment paper cups.

In a large bowl, using your hand mixer, cream the butter and sweetener together until smooth. Add each of the 4 eggs, mixing one at a time until mixture is creamy and fully incorporated. Add the lemon extract and continue to blend for 20 seconds.

In a separate bowl whisk together the almond flour, coconut flour, salt, baking powder, and xanthan gum. Make sure you break up all clumps of the dry ingredients and the xanthan gum is evenly incorporated. Slowly pour the dry ingredients into the wet ingredients and blend until fully mixed.

Pour in the cream and water into your mixture and stir until smooth. Gently add in blueberries..folding them into the lemon batter. Divide the batter between your 12 parchement cup lined muffin tins. Set aside.

Melt the butter and add the rest of the ingredients to the melted butter. Using a fork, stir until a crumbly dough forms. Using your clean fingers and hands, crumble the topping right over the tops of the muffin cups. There is a lot of crumble so I pack it on each muffin top using the cup of your hand and fingers.

Bake the muffins at 375 degrees for about 25 minutes. Using a toothpick to test for doneness helps take the guesswork out of the equation. Insert your toothpick or tester in the center of one of the muffins until it comes out clean will give you the answer of if you should take them out or leave them in for another few minutes. Remove muffins from the oven when you think they are done and let cool on the counter.

Whisk together the softened cream cheese, sweetner and lemon juice until smooth. Using a small plastic zip baggie, carefully spoon your cream cheese icing into the corner of the plastic baggie. You can cut off a very small tip of the baggie with scissors. Squeeze the baggie and decoratively drizzle the icing over the cooled muffins and serve.