Prep the pan and oven: Heat the oven to 350°F (175°C). Line an 8x8-inch baking pan with parchment, leaving a slight overhang for easy lifting. Lightly grease the parchment.

Melt the butter: In a microwave-safe bowl or small saucepan, melt 1/2 cup (113 g) unsalted butter until just liquid. Let it cool for a minute so it doesn’t scramble the eggs.

Whisk wet ingredients: In a large mixing bowl, whisk the melted butter with 2 large eggs and 2 teaspoons vanilla until smooth and glossy.

Add sweetener: Whisk in 3/4 cup granular keto sweetener until mostly dissolved. If using allulose, your brownies will be chewier and less likely to crystallize after cooling.

Mix dry ingredients: In a separate bowl, combine 1 cup almond flour, 1/2 cup cocoa powder, 1/2 teaspoon baking powder, and 1/4 teaspoon salt. Break up any lumps with a fork or whisk.

Combine: Add the dry mixture to the wet mixture. Stir with a spatula until just combined and no dry spots remain. The batter will be thick.

Optional add-ins: Fold in 1/3 cup sugar-free dark chocolate chips and 1/2 teaspoon espresso powder if using.

Spread and smooth: Scrape the batter into the lined pan. Smooth the top with a spatula, pushing into the corners.

Bake: Bake for 18–22 minutes. They’re done when the edges are set, the top looks slightly glossy, and a toothpick comes out with a few moist crumbs. Don’t overbake.

Cool completely: Place the pan on a rack and cool for at least 30–45 minutes. Lift the slab using the parchment and slice into 9–12 squares.