Preheat the oven to 300°F. Prepare a 9" round baking pan by spraying with nonstick spray and lining with parchment paper.
Separate the egg whites and yolks into two bowls. Beat the egg whites with an electric mixer, starting on low and gradually increasing to high speed, adding 1 tablespoon of sweetener until soft peaks form.
In the yolk bowl, mix the almond flour, nut milk, 2 tablespoons of sweetener, baking powder, vanilla extract, and a pinch of salt until smooth.
Gently fold a third of the whipped egg whites into the yolk mixture to lighten it, then fold in the remaining whites in two more additions, being careful not to deflate the mixture.
Pour the batter into the prepared pan, and arrange the sliced strawberries on top.
Bake for 55-60 minutes, or until a toothpick inserted into the center comes out clean.
Remove from the oven and immediately transfer the cake from the pan to a cooling rack.
Serve cooled, topped with strawberry-mint whipped cream.