Gather all of the ingredients you need for this recipe and preheat your oven to 350F. You'll also need to grease and flour a sheet pan.
Grab a bowl and add the following ingredients: butter. Cream the butter for a minute or two. Once smooth, add the sugar gradually and mix.
Add the eggs individually; only adding the next once the previous has been combined. Then add the vanilla extract, scraping the bowl as you go. Fold in the sour cream.
In a separate bowl, add the salt, baking soda and flour. Mix well and then in alternating additions, add the butter mixture and milk. Beat until just combined and then fold in the sprinkles.
Add the batter to your prepared pan and spread evenly. Place in the center of your preheated oven and bake for 22-24 minutes. Remove from oven and leave to cool.