Preheat the oven to 350°. Line a 9-by-13-inch metal baking pan with parchment paper, allowing overhang on the 2 long ends.
2
In a bowl, whisk the flour, baking soda and salt. In a large bowl, using a mixer, beat the butter with both sugars at medium speed until light, 1 minute. Beat in the eggs and vanilla. At low speed, beat in the dry ingredients. Stir in the chips and pretzels.
3
Spread the batter in the pan and top with the sprinkles. Bake for 30 minutes, until golden; the center will still be a little gooey. Transfer the pan to a rack and let cool completely.
4
Run the tip of a knife around the side of the pan and lift the bar out using the parchment paper. Cut into 24 squares and serve.