Summer dessert: Gooey cinnamon squares
Cookie Base:
8 tablespoons unsalted butter, at room temperature, plus more for the pan
1 ½ cups all purpose flour
1 teaspoon cream of tartar
½ teaspoon baking soda
¼ teaspoon kosher salt
¾ cup sugar
1 large egg
¼ cup milk
Gooey Layer:
¼ cup light corn syrup or honey
¼ cup milk, half and half or heavy cream
1 tablespoon vanilla extract
12 tablespoons butter at room temperature
1 cup plus 2 tablespoons sugar
¼ teaspoons kosher salt
1 large egg
1 ¼ cups all purpose flour
Topping:
2 tablespoons sugar
1 ½ teaspoons ground cinnamon
Preheat the oven to 350 degrees. Line the bottom of a 9 x 13 inch cake pan with at least 2 inch sides with parchment paper and either coat with butter or spray with baking nonstick spray. Set aside.
To make the cookie base, whisk together the flour, cream of tartar, baking soda and salt in a medium bowl. In the bowl of an electric mixer, beat the 8 tablespoons butter with sugar until light and fluffy. Add the eggs and the milk, and beat until combined, scraping down bowl and then beating for 10 seconds more. Beat in dry ingredients until just combined. Dollop cookie base over the bottom of the prepared pan and spread it into an even layer with a butter knife or offset spatula. Set pan aside.
To prepare the gooey layer, whisk corn syrup or honey, milk and vanilla together in a small bowl and set aside. In the bowl of an electric mixer, cream the butter, sugar and salt until light and fluffy. Beat in the egg, scrape down sides of bowl and mix 10 seconds more. Add 1/3 of flour and mix, then ½ of vanilla mixture and mix. Repeat again, twice, until all of the flour has been mixed until combined. Dollop over the cookie base and spread carefully with an offset spatula or butter knife.
To make the topping, mix the sugar and cinnamon in a small bowl and sprinkle it over the entire gooey layer. It will be thick but will come out of the oven almost like the top of a crème brulee. To bake and serve, bake for 25 to 30 minutes until the cookies have bronzed on top. The gooey layer will rise and fall in the oven but will still be a bit liquid-y under the cinnamon crust when the squares are done. Let cool completely on a rack, then cut into 1 inch squares.