Amazing Salted Caramel Bars - Chef Melt

Ingredients

• 4 1/2 tbsp unsalted butter, cut into pieces
• 90g water
• Kosher salt, a good pinch
• 150g granulated sugar
• 100g heavy cream, slightly warm
• 60g all-purpose flour
• 1 tsp vanilla extract
• 110g unsalted butter, softened
• 2 tsp vanilla extract
• 165g all-purpose flour
• 95g quick oats
• 1/2 tsp kosher salt
• 210g dark brown sugar, pressed tightly
• 1 large egg plus 1 yolk
• 1/2 tsp baking powder
• 95g chopped walnuts or pecans
• 85g semisweet chocolate chips
• 130g dark chocolate chips
• Flaky sea salt for sprinkling