Preheat oven to 350°F and spray a springform pan, tart pan, or cake pan with baking spray (see note).
In a bowl, cream together butter and sugars with an electric mixer for about 3 minutes until light and fluffy.
Mix in eggs, followed by vanilla extract. Beat for another 2 minutes until smooth and fluffy.
Sift in flour and baking soda. Fold with a rubber spatula until just incorporated.
Fold in mini chocolate chips.
Press dough into the bottom of prepared pan using hands or a spoon dipped in powdered sugar.
Add sprinkles and M&Ms evenly to top of dough.
Bake 20-25 minutes in preheated oven or until browned on the edges.
Cool in pan at least 30 minutes, then remove from pan and transfer to a cooling rack until completely cooled.
Use a piping bag to swirl frosting around the edge of cooled cake. Top frosting with M&Ms and sprinkles.
Pan choice: You can use a springform pan, tart pan, or cake pan for this recipe. If you are using a regular cake pan, add some parchment paper at the bottom of the pan to make it easier to remove the baked cake.Salted butter: I use salted butter in most of my baking, but if you prefer to use unsalted butter, just add in 1/2 tsp of salt into the dry ingredients.