Adapted from Smitten Kitchen, these bars tasted even better than I would have predicted when I was just testing the recipe. They freeze well and are easiest to slice when chilled.
Ingredients:
For the Crust:
1 ¾ cups unbleached all-purpose flour
½ tsp. kosher salt
1/3 cup granulated sugar
¾ cup plus 2 tbsp. chilled unsalted pareve margarine (14 tbsp.)
For the filling:
½ cup unsalted pareve margarine
½ cup granulated sugar
¾ cup demerara style brown sugar
½ tsp. kosher salt
3 large eggs
1 ½ tsp. pure vanilla extract
1 1/3 cups rolled oats
½ cup finely shredded coconut
1 ½ cups chocolate chips/chunks
Directions:
Preheat oven to 350F and line a 9-by-13-inch baking pan with parchment paper sprayed with nonstick spray. Combine the flour, salt, and sugar in the bowl of a food processor fitted with the steel blade.
Cut the margarine into chunks, and add it to the bowl, then run the machine until the mixture forms large clumps.
Transfer the dough clumps to the prepared baking pan and press them evenly across the bottom and ¼ inch up the sides.
Bake for 17 minutes, until very pale golden.
Melt the margarine for the filling in a medium saucepan over medium heat. Remove from the heat and stir in the sugars and salt.
Let cool for 5-10 minutes, then whisk in the eggs, one at a time, and the vanilla, and stir in the oats, coconut and chocolate.
Pour over the parbaked crust, spreading evenly.
Bake the bars for 23 more minutes until they are firm and golden and the bars are set.
Science Fact of the Week:
Normally recipes require softened butter or margarine., however for this one it uses chilled margarine. This allows the crust to have bubbles of margarine melt all around, giving it a flakey texture.
The Science of Baking 