Weigh out ingredients
You'll need flour, powdered sugar, butter, vanilla, brown sugar, condensed milk, corn syrup, dark chocolate, oil, and sea salt.
Make the shortbread base
Cream the butter and powdered sugar, then fold in the dry ingredients. Press into a 9x9 inch square pan and bake at 325 degrees F for 30-35 minutes.
Make the caramel filling
Heat everything over medium heat and whisk until it reaches 220 degrees F. Stir in the salt and vanilla, then pour over the cooled shortbread base. Chill in the fridge for at least two hours or overnight.
Cut the Twix Bars
Cut bars into 22 long bars or 44 small bars. Coat each bar in chocolate, then drizzle with more chocolate and sprinkle with sea salt.