Preheat oven to 350°F and spray mini muffin pan with non-stick cooking spray. Set aside.
In a large bowl, add brownie mix to the eggs and oil according to the box instructions. Mix until well combined.
Spoon brownie batter into the prepared pans filling each cup about half way.
Bake for approximately 12 minutes or until a toothpick inserted into the center comes out mostly clean.
Remove brownies from the oven and using a teaspoon push the bottom into the center of the brownie, creating a cup shape.
Set pan on a wire rack and allow brownies to cool completely before removing from the pan.
Using a microwave safe bowl add white chocolate and heat in 30 second increments, stirring in between until chocolate is fully melted. I like to add a little bit of Crisco to help the chocolate stay smooth. This is optional.
Once your melted chocolate is smooth, dip the tops of each brownie into the chocolate and then immediately add your sprinkles.
After the chocolate hardens, add the green frosting to a pastry bag. Then, pipe the the frosting upward creating a tree shape on top of the brownie cups.
Decorate your trees with more sprinkles and finish with a star sprinkle or other decoration to the top of each tree.