Step 1

Preheat oven to 350 degrees F (180 C). Set aside an 8x8 or 9x9-inch baking pan. Line the interior with parchment paper, if you like, to make it easy to lift out the baked brownies.

Step 2

In the microwave at 50% power or in a medium saucepan set over low heat, melt together the chocolate and butter, stirring frequently. When fully melted and smooth, remove from heat. Add the sugar, espresso powder, and eggs, whisking vigorously to fully incorporate. Add vanilla and sea salt and whisk again.

Step 3

Sprinkle flour and chocolate chips over the batter. Stir with a spoon or spatula just until combined. Scrape batter into the prepared baking pan, using the spatula to press batter into the corners if necessary.

Step 4

Bake 25-30 minutes, until a toothpick inserted into the center comes out with just a few crumbs. Let cool, cut, and serve.