Preheat the oven to 350ºF.
Next, coat a 8x8 baking dish with butter, oil, or nonstick cooking spray to prevent the brownies from sticking. Parchment paper could also be used instead.
Then melt the butter on the stovetop on medium-low heat with the 1/2 cup of chocolate chips, setting aside to cool a little afterward.
Next, sift all dry ingredients together.
Then you can stir in the melted butter and melted chocolate into the dry mix, adding the eggs and vanilla extract next.
Be sure to mix thoroughly until everything is homogeneous, but do not overmix.
Last, fold in the remaining 1/3 cup of chocolate chips, along with the sprinkles, into the batter without overmixing.
Then pour the batter into the baking dish, using a spatula to smooth the batter out evenly.
Bake in the oven, at 350º F, for about 30-40 minutes.
Remove brownies from the oven when a toothpick comes out clean about an inch from the edges. The center will firm up more once the brownies cool down.
Cool for two hours before slicing. Slice into 9 pieces and serve.