Preheat the oven to 350F. Spray the tart pan with non-stick cooking spray.
Combine the almond flour and melted butter, then press into the tart pan, forming a crust.
Bake the crust for 10 minutes, then remove from the oven and let cool.
Meanwhile, add heavy cream and powdered erythritol to a large bowl. Whisk on medium speed with an electric mixer until stiff peaks form (5-10 minutes).
Add whipped cream to the crust and top with berries.