Preheat oven to 350ºF. Spray a 9×13 baking dish with nonstick cooking spray.

Mix together butter and sugar using an electric mixer until fluffy.

Mix in the eggs and the vanilla extract. Then stir in the baking soda and cream of tartar.

Slowly mix in 4 cups all-purpose flour (a little at a time) until the mixture is combined (don’t overmix)

Finally, stir in the chocolate chips. Batter will be very stiff so this will take a couple of minutes.

In a bowl, whisk together caramel sauce and 1/4 cup all-purpose flour until totally combined.

Press half of the cookie bar batter into the bottom of the prepared baking dish and halfway up the sides.

This is easiest if you spray a little nonstick spray onto your hands and then press the batter gently.

Pour caramel sauce on top of batter.

Drop spoonfuls of the remaining dough evenly over the top of the caramel

Bake for about 25-35 minutes until golden brown. Cool completely before cutting.