• Preheat oven to 350 degrees F. (Make sure oven rack is in the middle of the oven.)
• Grease a 9x13 inch pan and line it with a parchment sling

For the Filling

• In a large bowl, whisk together the sweetened condensed milk, lemon juice, heavy cream, zest, vanilla, and salt. Set aside.

For the Crust

• In a bowl of a stand mixer fitted with a paddle attachment, mix the flour, oats, brown and granulated sugars, baking soda, and salt on low speed until combined.
• Add the butter and increase the speed to medium, mixing until the mixture is crumbly.

Assemble the Bars

• Press half of the oat mixture to the bottom of the prepared pan and bake for 10 minutes.
• Remove the pan from the oven and spread the filling over the crust.
• Sprinkle the remaining oat mixture evenly over the top.
• Bake for 15-20 minutes until the filling is set. It should not jiggle and the oat topping should be a light golden brown.
• Transfer pan to a wire rack and cool.
• Place the pan in the refrigerator and chill for 4-6 hours.
• Slice and serve your Lemon Oat Bars!