Turn the oven to 350°F (180°C).
Grease or spray an 8-inch (20cm) square pan. Line with a strip of parchment paper wide as the pan, covering the bottom and two sides. This makes it easier to remove from the pan after it’s baked.
Melt ¾ cup unsalted butter in a bowl 3 ½ ounces semisweet chocolate in pieces. You can microwave it in 10 second spurts, mixing well between each one. Or do it in a double boiler making sure the bottom of the bowl is not touching the water.
Combine 1 cup white granulated sugar and 2 tablespoons brown sugar in a bowl, add the 3 eggs and mix well with a whisk until it’s frothy, about 1 minute.
Add the melted chocolate mixture and stir until fully mixed.
Add 1 teaspoon vanilla extract , ¼ teaspoon pure almond extract and then the sifted dry ingredients (½ cup all-purpose flour, ½ cup unsweetened cocoa powder and ½ teaspoon salt) in 2 parts. I have them measured and sift them directly over the chocolate mixture, but you can sift them in a different bowl first and then add them.
Mix well until you have a silky, smooth mixture.
Pour into the prepared pan and bake for about 20 minutes, until the edges are firm but the center still jiggles. It might take a few more minutes. But don’t bake them until the whole surface is firm because they won’t be fudgy.
Let cool on a wire rack. I recommend eating them the next day, but that’s hard, I know. So pop them in the fridge for an hour.
Eat them plain or top with chocolate sauce, dulce de leche and ¼ cup chopped walnuts before eating.