Line 2 large baking sheets with parchment paper. Set aside.
In a bowl, whisk together the flour, cornstarch, salt, and baking powder. Set aside.
In a mixing bowl, using a hand mixer or stand mixer, beat the butter and brown sugar together on high until light and fluffy, about 2 minutes.
Beat in the egg and vanilla extract until fully combined, about 30 seconds.
Add the dry ingredients to the mixing bowl and beat on low just until combined. Do not overmix.
Fold in the sprinkles.
Cover the bowl and refrigerator for 30 minutes before rolling out.
Lightly dust a clean work surface with flour. Place 1/3 of the dough on the work surface and roll it out to 3/8” thickness.
Using a crinkle cutter or sharp knife, cut the cookie fries about 1/2 inch in width and 4 inches long. It’s fun to make them all slightly different sizes to vary the appearance, like real fries.
The dough needs to chill in the freezer before cooking. Place them on baking sheets that can fit into the freezer and freeze it for 20 minutes.
Preheat the oven to 350°F(175°C).
Remove from the freezer and place one tray at a time in the oven on the center rack and bake for 10-12 minutes. They will still be soft. They’ll continue baking on the hot tray after they’ve been removed from the oven.
For the dip, mix the cream, cream cheese, and powdered sugar in a bowl and stir until smooth. Serve in a bowl on the side of the fries.