4 ounces (aka 1 stick) unsalted butter, cut into pats
2 ounces unsweetened chocolate, coarsely chopped
1 cup sugar
2 large eggs, at room temperature
1 teaspoon vanilla extract
100 grams teff flour (a generous 3/4 cup)
1/2 teaspoon coarse salt
2 handfuls chopped hazelnuts or walnuts
2 handfuls chopped semisweet chocolate, or chocolate chips
Preheat the oven to 350° Fahrenheit. Line an 8-inch baking pan with greased foil or parchment paper, or grease and flour. Set aside.
In a double-boiler (or in bursts in the microwave), melt the butter and chocolate. Stir to combine, and let cool until it's no longer too hot. Add the sugar, stir, and then add the eggs, stirring in between (mix until the eggs are incorporated, but no need to whip the bejesus out of it — you're not looking to incorporate air). Add the vanilla, stir, then add the teff flour and salt, and stir until combined. Fold in the nuts and chopped chocolate.
Pour the batter into the prepared pan, and spread it out evenly. Bake until the center is just starting to set and the edges pull away from the sides, ~20-25 minutes (I consider over-baked brownies to be one of the sadder kitchen outcomes, so I make sure to check it regularly as it approaches this stage). Remove from the oven, and let cool on a rack. Slice and enjoy.