Preheat oven to 350 degrees Fahrenheit. Grease a nine-inch square or round pan and line it with Gefen Parchment Paper. Lining it with parchment paper helps the brownies come out of the pan with no fuss or mess.

In a medium or large size bowl, add in the flour, cocoa powder, and sugars. Whisk until combined.

Add oil, eggs, coffee, and rum. Mix until all the ingredients are incorporated.

Pour the batter into the pan and sprinkle the crushed walnuts over top.

Bake for 25-30 minutes. You will know the brownies are ready when you stick a toothpick to the center and it comes out clean.

Allow the brownies to cool for 10 minutes before touching them. Remove the brownies from the pan, slice them up, and enjoy them warm. Cover them and store them at room temperature for one week or in the fridge for two weeks. If storing them in the fridge, heat the brownies on a microwave-safe dish for 20 seconds. You can also freeze them for up to three months.