Prepare and bake your brownies in a very well greased 9 inch round pan. I used a box mix, and baked mine for 40 minutes.
Allow the brownies to cool completely, then refrigerate for 30-45 minutes to help making cutting and removing from the pan easier..
Remove the brownies from the refrigerator, and gently run a butterknife around the edges of the pan to help loosen the brownies. (This is why you need a very well greased pan, so this step is easy!) If needed, gently run your knife along the bottom edge of the pan too.
Set the entire round batch of brownies on a cutting board or platter, and use a sharp butcher knife to cup the brownies into 8 triangles, slicing it like a pie.
Arrange the triangles in a row, with the wider edge at the bottom to make decorating easier.
Snip off the end of your icing, and moving your hand in a zigzag motion, create a “tree” on the brownie.
Decorate with sprinkles.
Add a tiny dot of icing to the bottom of a Reese’s Miniature, and secure it to the bottom of the brownie tree.
Notes
Don't have a Piping Bag: Use a plastic bag or buy tubes of premade icing tubes.
Premade Brownies: If you do not want to use a boxed mix use a premade brownie.
Cool: Let the brownies cool completely before attempting the frosting.
Variation tip: Use a round cookie cutter and then decorate these brownies like Christmas ornaments.