Preheat the oven to 350F; line a baking sheet with a piece of parchment paper or a silpat liner.
Use a fork to stir together the almond flour, tapioca starch, coconut sugar, salt, baking powder, and mahlab in a medium bowl. Stir in the egg white and vanilla (the dough will be sticky).
Drop the dough onto the prepared baking sheet (sort-of like a drop biscuit; don’t flatten it). Bake until the biscuit is puffed and the bottom is golden, about 20 to 25 minutes. Cool.
While the shortcake bakes, stir together all ingredients for the strawberries in a small bowl. Transfer to the fridge to macerate for at least 15 minutes.
To serve, split the cooled biscuit in half, spoon the berries on top, and dollop on the whipped cream.
Notes
Nutrition information is for the whole recipe, but doesn't include the coconut "whipped cream".
To make coconut “whipped cream”, refrigerate a can of unsweetened, full-fat coconut milk (while still in the can) until fully chilled, 8 hours or overnight. Open the can from the bottom and drain off the thinner, liquid-y coconut milk (you can reserve it for use in something else, such as a smoothie, if you want). Transfer 3 tablespoons of the thick, waxy-looking portion to a medium bowl, and whip it with a handheld electric beater until light and fluffy. Or you can use regular whipped cream, if keeping it paleo isn’t a concern.
If you want to double the recipe, use 1 large egg instead of 2 large egg whites. All other ingredients are easy to double.