In a bowl combine coconut flour, almond flour, sweetener, salt, Xantan gum and butter. Stir to combine.
Spray a muffin tin with cooking spray (you can use coconut oil spray).
Press about 1 tbsp of the mixture to the bottom of each muffin tin slot, pressing up towards the walls about 1/4 inch.
Bake for 5 minutes, then cool for 15 minutes.
Heat 1/4 cup of heavy cream, bringing it to a simmer. Add the lavender flowers and cover. Steep for 5-10 minutes, then strain. Chill the heavy cream for 30 minutes.
Add the remaining heavy cream to the lavender infused one.
Beat mascarpone with sweetener for 30 seconds on low speed.
Slowly, while still beating on medium-low, add the heavy cream to the mascarpone. Beat for 1-2 minutes, until it reaches the texture of thick heavy cream. Do not over beat, because the cream mascarpone will separate.
Very carefully remove each shell from the muffin tin.
Fill with lavender whipped cream. Top with blackberry. Serve.