In a medium bowl, toss the berries with sweetener, lemon juice and xanthan gum, if using. Pour into a lightly greased pie pan.
Rinse and dry the same bowl and add the almond meal, nuts, coconut oil, vanilla, cinnamon, and salt. Use a fork or clean hands to combine the mixture until it forms small pea-sized clumps.
Spread mixture evenly on top of berries with your hands and press down lightly.
Bake for 28 to 35 minutes, or until golden brown and the edges are bubbling. Serve warm.