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

Mix dry ingredients: In a large bowl, whisk almond flour, cocoa powder, sweetener, baking powder, and salt until no lumps remain. Breaking up cocoa clumps now prevents streaks later.

Combine wet ingredients: In a separate bowl, whisk the melted butter, almond butter, eggs, vanilla, and espresso powder until smooth and glossy.

Bring it together: Pour the wet mixture into the dry ingredients. Stir with a spatula until just combined. If using chocolate chips, fold them in gently.

Spread and level: Scrape the batter into the prepared pan. It will be thick; use a spatula to smooth the surface. Sprinkle with flaky salt if you like.

Bake: Bake for 18–22 minutes, depending on your oven and preferred fudginess. Pull them when the center is just set and a toothpick comes out with a few moist crumbs, not wet batter.

Cool completely: Let the pan cool on a rack for at least 20–30 minutes. Lift the brownies out with the parchment and allow to cool another 10 minutes before slicing. This step sets the fudgy texture.

Slice and serve: Use a sharp knife and wipe between cuts for clean edges. Enjoy warm, at room temperature, or chilled for extra chewiness.