Heat the oven to 350, and grease an 8x8 inch baking dish.
Whisk the egg yolk, lime juice, zest and sweetened condensed milk together in a small bowl until smooth.
1 Tablespoon Lime Zest, 1/4 Cup Lime Juice, 1 Large Egg Yolk, 14 Ounces Sweetened Condensed Milk
In a separate bowl, using a pastry cutter, or fork, mix together the flour, butter, brown sugar, oats, baking soda and salt. At the end I like to use my hands to incorporate the butter a little more evenly into the mix.
10 Tablespoons Butter, 1 Cup Flour, 1 Cup Brown Sugar, 1 Cup Oats, 1 teaspoon Baking Soda, 1 Pinch Salt
Press half of the dry oat mixture into the pan and bake for 9-10 minutes.
Remove from the oven and pour the Lime mixture over the crust.
Sprinkle the remaining oat mixture evenly over the top and place back in the oven for an additional 15 min.
Allow to cool and place in the fridge for 1-2 hours and serve.
Notes
*I get the the butter out about 15 minutes before I need it and let it sit on the counter. This way it isn't rock solid, but still has a chill on it when I go to mix it in.Store left overs in the refrigerator