Salted Caramel Brownies Gelson's

Ingredients

• 6 Tbsp unsalted butter, diced
• ½ cup vegetable oil
• 10 oz bittersweet chocolate, chopped
• 1 ½ tsp espresso powder
• ¾ cup granulated sugar
• ½ cup firmly packed brown sugar
• 4 large Gelson’s eggs, plus one egg yolk
• 2 tsp vanilla extract
• 1 cup all-purpose flour
• ¾ tsp kosher salt
• 1 ½ cups Gelson’s walnut pieces, toasted, plus more for serving
• 1 cup semisweet chocolate chips
• 1 ½ cups salted caramel sauce
• Flake salt, for garnish