Prep your pan and oven: Heat the oven to 350°F (175°C). Grease a 9-inch tart pan with a removable bottom. You can also line the base with parchment for easy release.

Make the crust: In a bowl, mix 2 cups almond flour, 3 tablespoons granulated keto sweetener, a pinch of salt, 5 tablespoons melted butter, and 1 beaten egg until a soft dough forms. It should hold together when pressed.

Press and dock: Press the dough evenly into the tart pan, going up the sides. Use a fork to prick the base a few times to prevent puffing.

Bake the crust: Bake 12–15 minutes, until the edges are golden and the center looks set. Cool completely on a rack so the filling won’t melt into it.

Cook the raspberry base: In a saucepan over medium heat, add 2 1/2 cups fresh raspberries, 1/3 cup granulated keto sweetener (adjust to taste), 1 tablespoon lemon juice, and 1 teaspoon lemon zest. Cook 5–7 minutes, stirring and lightly mashing, until juicy and slightly thickened.

Strain (optional): For a seedless texture, press the warm mixture through a fine sieve into a bowl. If you like seeds, skip this step.

Bloom the gelatin: In a small bowl, sprinkle 1 1/2 teaspoons powdered gelatin over 2 tablespoons cold water. Let it sit 5 minutes to bloom. For agar-agar, check package directions; you’ll usually simmer it in liquid to activate.

Set the filling: Stir the bloomed gelatin into the warm raspberry mixture until dissolved. Add 1/2 teaspoon vanilla and a tiny pinch of salt. Taste and adjust sweetener or lemon as needed.

Assemble the tart: Pour the raspberry filling into the cooled crust. Smooth the top with a spatula. If using extra fresh raspberries on top, arrange them gently now or after it sets.

Chill: Refrigerate 2–3 hours, or until the filling is fully set and slices cleanly.

Finish and serve: Before serving, top with lightly sweetened whipped cream or coconut cream and a sprinkle of lemon zest or sliced almonds. Slice with a sharp knife, wiping between cuts for neat edges.