Preheat oven to 350 degrees Fahrenheit.
Cover the bottom of a 8x8-inch baking dish with parchment paper, allowing the parchment paper to overhand on two sides. Grease the sides and bottom of the pan with butter or cooking spray.
In a medium bowl, add almond flour, cocoa powder, baking powder, salt, and instant espresso powder and whisk until combined. Set aside.
In a large bowl, add melted butter and sugar. Using a hand mixer, mix together for 1-2 minutes, until light.
Add the eggs and vanilla and mix thoroughly until combined.
Gradually add in the dry ingredients and mix until just combined and no streaks of the almond flour mixture remain.
Reserve one tablespoon of the chocolate chips. Stir the remaining chocolate chips into the brownie batter.
Pour brownie mixture until prepared baking pan. Top with remaining one tablespoon of chocolate chips and the fleur de sel.
Bake at 350F for 22-25 minutes, rotating the pan halfway through. Bake until the edges of the brownies are set. A toothpick inserted into the middle should come out relatively clean, but some wet crumbs are okay. Do not over bake.
Allow to cool completely before lifting the brownies out of the pan using the parchment paper. Slice into squares.