Begin by preheating your oven to 350°F and prepare a 9x13” metal baking pan lined with foil and coated with cooking spray.

In a mixing bowl, beat together the butter and brown sugar until the mixture is crumbly. Then incorporate the eggs and vanilla, mixing until smooth.

Next, add the salt and baking powder, then mix in the flour. Carefully fold in the M&Ms and sprinkles, ensuring an even distribution.

Transfer the mixture into the prepared baking pan, using cooking spray on your hands to help spread it evenly. Add any leftover M&Ms and sprinkles on top.

Bake in the oven for 22 to 25 minutes, until they are a lovely golden brown, being sure to take them out slightly underbaked.

Allow the bars to cool before slicing. Store in an airtight container for up to 4 days or freeze them for a month for later enjoyment.