Preheat the oven to 350 F. Generously grease a 9x13 baking dish.

In a large bowl, add the butter, brown sugar, granulated sugar, eggs, and vanilla extract. Mix well until smooth and combined.

Add the flour, salt, baking soda, and baking powder to the bowl. Mix until smooth and cohesive.

Fold in the chocolate chunks and sprinkles, reserving some for the top of the bars.

Pour the batter into the baking dish, using a spatula to spread it evenly and smooth it on top. Add extra chocolate chunks and sprinkles to the top of the batter.

Bake in the preheated oven for 30-35 minutes, or until the top is golden and a knife inserted in the center comes out only a little wet. Let the bars cool fully - they will continue to cook while they cool - and then cut into slices and serve.