I bake the brownies for 20-25 minutes. The key to fudgy brownies is to not overbake them. I start checking at 20 minutes. The edges should be set and pulling away slightly from the pan, and a toothpick inserted into the center should come out with a few moist crumbs clinging to it—not clean, but not covered in wet batter. If it’s clean, they’re overdone. I remove the pan to a wire rack and let the brownies cool completely in the pan. This patience is hard but essential before frosting.
While the brownies cool, I make the coffee frosting. In my other bowl, I beat the softened butter with a hand mixer until creamy. I add the sifted powdered sugar, the remaining 1 1/2 tsp of instant coffee (I often crush it first or dissolve it in 1 tsp of the heavy cream), vanilla, and a pinch of salt. I start mixing on low, then add the heavy cream one tablespoon at a time until I reach a spreadable, creamy consistency. I beat it for 2-3 minutes until it’s light and fluffy. Once the brownies are completely cool, I spread the frosting evenly over the top. I then lift the whole slab out using the parchment paper and cut it into neat squares.
Pro Tips for Best Results
For the most intense, non-gritty coffee flavor in the frosting, dissolve the instant coffee granules in the vanilla extract or in one teaspoon of very hot water before adding it to the butter and sugar. I’ve tried just adding the dry granules, and sometimes they don’t fully dissolve, leaving tiny crunchy bits. Dissolving them first guarantees a perfectly smooth, flavorful frosting every time.
To achieve the ultimate fudgy texture, avoid overmixing the batter once the flour is added. Stir just until the flour disappears. Overmixing develops gluten, which can make the brownies more cake-like and less dense. Also, be brave and pull them from the oven when the center is still slightly soft—they will continue to set as they cool.
For picture-perfect clean cuts, I use a sharp knife and wipe it clean with a hot, damp cloth between each cut. I also chill the frosted brownies in the fridge for about 30 minutes before cutting. This firms up the frosting and makes slicing through the dense, fudgy layers much easier, giving you those sharp, professional edges.
Common Mistakes to Avoid
The biggest mistake is overbaking. I learned this the hard way with my first batch. I left them in just 5 minutes too long, and while they were still tasty, they were cakey and dry, not fudgy and moist. Trust the toothpick test with moist crumbs and remember they will keep cooking from residual heat in the pan.
Don’t try to frost warm brownies. I was once too eager and spread the frosting on brownies that were still slightly warm. The butter in the frosting melted on contact, creating a greasy, thin layer that soaked into the brownie top instead of sitting prettily on it. Let them cool completely to room temperature.
Avoid using brewed coffee or espresso in place of the instant granules. The extra liquid will ruin the carefully balanced ratio of wet to dry ingredients in both the brownie and the frosting. Instant granules provide pure coffee flavor without the water. This ingredient choice makes a huge difference.(See the next page below to continue…)