• Preheat the oven to 350 degrees F. Line a 9x13-inch baking pan with foil and nonstick spray.
• Beat the butter and sugars until smooth, about 1 minute. Add in the eggs and vanilla and beat again.
  1 Cup Unsalted Butter, 1/2 Cup Granulated Sugar, 1 1/2 Cups Brown Sugar, 2 Large Eggs, 2 teaspoons Vanilla Extract
• Stir together the cream of tartar, salt, nutmeg, baking powder, cinnamon and flour. Add to the butter mixture and beat until combined.
  1 teaspoon Cream of Tartar, 1/2 teaspoon Salt, 1/2 teaspoon Nutmeg, 1 teaspoon Cinnamon, 2 3/4 Cups Flour, 1 teaspoon Baking Powder
• Divide dough in half.
• Press half of the dough into the pan. Set the other half aside.

For the Cheesecake

• Beat the cream cheese until smooth. Add the sugar and vanilla and beat again. Finally, add the egg and mix until combined. Do not over-beat.
  8 Ounces Cream Cheese, 1/2 Cup Sugar, 1 teaspoon Vanilla, 1 Large Egg
• Pour the cheesecake on top of the cookie dough.
• Crumble the remaining dough on top of the cheesecake.
• In a small bowl, mix the cinnamon and sugar and sprinkle all of it on top of the bars.
  2 teaspoon Cinnamon, 3 Tablespoons Sugar
• Bake for 30 minutes, carefully remove to a wire rack or on hot pads to cool on the counter for 1 hour.
• Place in the refrigerator and chill for 2-3 hours before slicing and serving.