Step 1

In a medium bowl whisk together the flour, baking soda, baking powder, cornstarch, and salt.

Mix Dry Ingredients 

In a large bowl combine melted butter and sugar.

Mix the Butter and Sugars

Step 2

Then mix in the egg and egg yolk, mix until fully incorporated.

Add Eggs

Step 3

Mix in cookie butter, whisk until fully combined.

Add Cookie Butter

Step 4

Then fold in the dry ingredients.

Add dry to wet

Step 5

Once almost combined mix in the chocolate chips.

Add Chocolate Chips

Step 6

Pour half of the batter into the prepared pan then scoop the remaining cookie butter into the pan and use a knife to swirl it around

Prepare the pan

Step 6

Add the remaining cookie dough and spread it into an even layer.

Add the Dough and Bake

Step 7