Preheat your oven to 350°F (175°C). Line an 8x8-inch pan with parchment, letting the paper hang over two sides for easy lifting.

Make the crust: In a bowl, mix almond flour, powdered sweetener, and salt. Stir in vanilla and the melted butter until the mixture looks like damp sand and holds together when pressed.

Press the crust evenly into the lined pan. Use the back of a measuring cup to smooth it out. Bake for 10–12 minutes until just set and lightly golden at the edges. Set aside to cool slightly.

Toast the pecans: Spread chopped pecans on a sheet pan and bake for 5–7 minutes, until fragrant. Let cool.

Brown the butter: Place 10 tablespoons butter in a light-colored saucepan over medium heat. Cook, stirring, as it foams, then turns golden. Watch for brown specks and a nutty aroma, 5–7 minutes total. Remove from heat immediately to prevent burning.

Make the filling: While the brown butter is still warm, whisk in the brown-style sweetener and allulose/erythritol until dissolved. Let cool 2–3 minutes so it’s warm, not hot.

Whisk in eggs, vanilla, maple extract (if using), salt, and heavy cream. Mix until smooth and glossy. Stir in the toasted pecans.

Pour filling over the parbaked crust and spread evenly. Tap the pan once to release air bubbles.

Bake for 18–22 minutes, until the edges are set and the center jiggles slightly but isn’t wet. The top will look glossy with a few bubbles.

Cool in the pan on a rack for at least 1 hour, then refrigerate 1–2 hours for clean slices. Lift out by the parchment and cut into 16 bars.

Finish with a pinch of flaky sea salt, if you like, to balance the sweetness.