Whisk together the flour, pretzels, baking soda, and salt. Set aside.

Using an electric mixer on medium speed, beat the butter, sugar, and brown sugar until light and fluffy. Add the eggs and mix well.

Reduce mixer speed to low. Gradually add the flour mixture, mixing until almost combined. Stir in the oats.

Reserve 1 cup of the mixture for the topping. Transfer the remaining mixture to the prepared pan and press evenly.

Place the condensed milk and caramels in a medium saucepan. Cook, stirring constantly, over medium-low heat until the caramels have melted and the mixture is smooth.

Remove from heat and stir in the vanilla. Pour the mixture over the oat mixture in the pan. Spread evenly.

Sprinkle the cashews, chocolates, and sea salt over the caramel. Drop the reserved oat mixture over the bars.

Bake 25 to 30 minutes, or until the bars are light brown.

Cool completely in the pan on a wire rack. Use the edges of the lining to lift the bars out of the pan and onto a cutting board. Use a sharp knife to cut into bars.