Well, first you'll need to gather all the ingredients for the brownies, like flour, sugar, cocoa powder, eggs, butter, and vanilla extract. Once you have those, you can mix them together in a bowl and then pour the batter into a greased and floured pan. Bake the brownies in the oven until they're golden brown and a toothpick inserted into the center comes out clean. Finally, you can decorate the brownies to look like a christmas tree, using green frosting and sprinkles. Enjoy!