Fudgy Salty Peanut Butter Brownies

INGREDIENTS

• 1 cup powdered sugar
• 1 1/4 tablespoons milk
• 1 1/2 cups semisweet chocolate chips
• 7 tablespoons unsalted butter
• 1 1/4 teaspoon pure vanilla extract
• 1/4 teaspoon fine sea salt
• 1 teaspoon pure vanilla extract
• 1/2 stick unsalted butter, at room temperature
• 1 cup creamy peanut butter (don't use old-fashioned or natural)
• 2 cups semisweet chocolate chips
• 2 eggs, at room temperature
• 1 1/3 cups sugar
• 1/2 teaspoon fine sea salt
• 2/3 cup all-purpose flour
• 1 1/4 sticks unsalted butter, plus more, softened, for pan
• 1 cup unsweetened natural cocoa powder
• 1 1/2 cups salted cocktail peanuts