• Preheat the oven to 350F degrees. Line an 8x8 inch square baking pan parchment paper leaving an overhang around the edges, or line with aluminum foil and lightly grease.

Oatmeal Cookie Layer

• In a large bowl whisk together the butter and sugars. Then whisk in the egg and vanilla. 
• Fold in the flour, salt & cinnamon, followed by the oatmeal.
• Spoon about three quarters of the mixture into the bottom of your prepared pan to create an even layer of oatmeal cookie mixture. Set the remaining oatmeal mixture aside (about ½ - ¾ cup).

Chocolate Fudge Layer

• Add about ½ inch of water to a medium saucepan over low-medium heat and place a large glass bowl over top (ensure the bottom of the bowl doesn't touch the water).
• Add the chocolate chips, sweetened condensed milk and butter to the glass bowl. Gently stir the mixture as it melts.
• Once the mixture is a smooth consistency, remove the pan from the heat.

Assemble and Bake

• Pour the chocolate mixture over top of the oatmeal cookie layer.
• With the remaining oatmeal mixture, drop tablespoons sized amounts over the chocolate fudge so that some fudge is showing.
• Bake in the preheated oven for about 25-30 minutes. The pieces of oatmeal cookie on the top should look set. Cooking the bars for longer will result in crispier, less chewy bars.
• Allow the bars to cool fully (about 3 hours). Lift the bars out of the pan using the overhang from the parchment paper/aluminum foil and place on a cutting board. Slice into bars using a sharp knife.