Using mixer, beat the butter, sugar, and brown sugar on high speed for 2 minutes. Add in the milk and vanilla, scrape the bowl, and beat on high until combined.
1/2 cup Unsalted butter, 2 TBSP White granulated sugar, 3 TBSP Brown sugar, 1 tsp Pure vanilla extract, 2 TBSP Milk
Add in the flour, cornstarch, and salt. Mix on low until just combined. Add in the mini chocolate chips. Set aside.
1 1/2 cups All-purpose flour, 1/2 tsp Cornstarch, 3/4 cup Mini chocolate chips, 1/2 tsp Salt
On a lightly floured surface, roll the dough out using a rolling pin. Roll until 1/4 inch thick. It should be a large rectangle.
Spread the cinnamon filling using an offset icing spatula. Take little bit of cookie dough at a time in your hands. Use your hands to flatten the dough into a pancake. Place over the filling. Do this until you only have a 1/4 cup of cookie dough left.
Roll the dough into a log started on the short side. Use a serrated knife to cut off the uneven ends. The, cut into 12 even rolls.
Spray a 9X13 pan with baking spray. Place the rolls in the pan. Cover with a towel and let rise for 20 minutes.
Preheat the oven to 375℉. Bake the rolls for 28-30 minutes. Bake until the top is lightly golden.