Preheat your oven to 350 degrees F. Line a baking sheet with parchment paper.
In a medium bowl, whisk together the egg, sour cream, vanilla, stevia, and salt. Using a rubber spatula, mix in the almond flour, then the baking powder.
Using a large 4-tablespoon scoop, place 4 mounds of the dough on the prepared baking sheet. Very lightly flatten the tops, not too much or they'll be too flat to slice.
Bake until golden, 15-18 minutes. Turn the oven off, remove the biscuits, and place them in the fridge on paper towels to quickly chill them while you make the filling.
Make the filling and topping:
Cut two of the strawberries in half. You'll use these four halves to top the cakes. Slice the remaining strawberries into ⅛-inch slices.
Place the whipping cream, vanilla and stevia in a mini food processor bowl*. Process on high (if you have a "grind" and a "chop" setting, use the "chop" setting) until the mixture turns into whipped cream, 30-60 seconds. Make sure not to over-process. ¾ cup liquid cream should yield about 1 ½ cup of whipped cream.
Carefully slice each biscuit horizontally. Arrange 4-5 strawberry slices on the bottom half. Spoon about ¼ cup of whipped cream on top of the strawberries. Top with the second biscuit slice. Garnish with a dollop of whipped cream and a halved strawberry. Repeat with the three remaining biscuits.
Serve immediately, or keep at room temperature for up to an hour before serving.
* You can also whip the cream the old-fashioned way, in a cold mixing bowl using a handheld electric whisk with cold attachments. If you go this route, whip the cream until it starts to thicken, then add the vanilla and stevia and continue to beat until firm, taking care not to overbeat.