Heat the oven to 325°F and line an 8-inch square pan with parchment paper. Mix the almond flour, powdered allulose, salt, and melted butter for the crust, then press firmly into the pan.
Bake the crust for 8 minutes. Remove it from the oven and let it cool slightly.
Beat the cream cheese and powdered allulose until smooth. Mix in the eggs one at a time, then blend in the sour cream, vanilla, and strawberry extract before folding in the diced strawberries.
Spread the filling over the crust and bake for 34 to 38 minutes, until the edges are set and the center still has a gentle jiggle. Cool completely, then refrigerate for at least 4 hours.
Stir the almond flour, powdered allulose, strawberry powder, salt, and melted butter for the crunch until crumbly. Spread on a parchment-lined baking sheet and bake at 325°F for 7 to 9 minutes, stirring once, then cool completely.
Beat the cold heavy cream with the powdered allulose until medium peaks form.
Spread the whipped cream in a thin layer over the chilled cheesecake. Scatter the strawberry crunch generously over the top and press it on very lightly.
Chill for 20 minutes more, then cut into squares and serve cold.