Preheat the oven to 350 degrees F and line a 9”x9” pan with parchment paper. In a stand mixer with a paddle attachment, cream together the butter and sugar until light and fluffy.
Add the eggs in one at a time, mixing well in between. Add in the vanilla and mix again.
In a medium sized bowl, whisk together flour, cornstarch, salt, and baking soda.
Slowly add the dry ingredients into the wet ingredients and mix until combined.Add the nonpareils into the dough and mix.
Add in the chopped animal crackers.
Fold in the animal crackers to the dough.
Gently press the dough into the prepared baking pan.
Bake for 25-30 minutes, or until the cake tester comes out clean.
Notes
You can use rainbow sprinkles in place of the nonpareils.
These can be frozen, see my tips above.
You can double this recipe and bake in a 9"x13" bar pan or baking pan.