Preheat The Oven & Prep The Pan. Start by preheating the oven to 350 degrees F. Line an 8x8 metal baking pan with parchment paper. (Use metal instead of glass or ceramic, or the brownies will climb the sides of the pan.)
Melt The Chocolate & Butter. In a small saucepan, gently melt the chocolate and butter together. on low heat, stirring until smooth. You can also do this in a microwave-safe bowl, melting in 20-30 second increments in the microwave, stirring after each interval. Remove the pan from the heat.
Stir In The Vanilla, and mix until smooth and glossy.
Whip Sugar & Eggs. In a large mixing bowl, combine the sugar and eggs. Whisk or beat until the sugar has dissolved and the egg mixture has lightened in color significantly. (When you rub the mixture between your fingers, there should be almost no grit at all.) This will take several minutes by hand, or 2-3 minutes with a hand mixer.
Combine Eggs. & Chocolate. Pour the partially cooled mixture into the egg mixture and stir to combine.
Mix In Dry Ingredients. Add gluten-free flour, cocoa powder and salt to the batter and stir until just combined and no dry patches remain.
Pour Into The Pan & Bake. Pour the brownie batter into the prepared pan and bake at 350 degrees for 20-23 minutes, or until the brownies are set on the top. (Try not to over-bake here or the brownies will go dry.)
Cool Completely Before Topping. Let the brownies cool to room temperature before adding the crunch topping. (You can speed this up by popping them into the fridge to cool down)