1. Preheat the oven to 350°F. Grease a 9-inch by 13-inch pan and set aside.
2. In a saucepan over medium heat, melt the butter and brown sugar, stirring constantly until smooth. Remove from the heat, and stir in the peanut butter, until creamy and combined. Set mixture aside to cool.
3. In a large bowl, whisk together flour, baking powder, baking soda, and salt.
4. Add the eggs, one at a time, to the peanut butter mixture, mixing well after each addition. Add the vanilla extract and stir to combine. Pour the mixture into the prepared dry ingredients, and stir until batter is smooth. Stir in the white chocolate chips, peanut butter chips, and peanuts.
5. Transfer the batter to the prepared pan, spreading the batter evenly to the edges of the pan. Sprinkle with sea salt.
6. Bake for 25 minutes and remove from the oven. Gently press candy corn into the blondies. Put pan back in the oven and bake for an additional 2-4 minutes. The top should be golden and the edges slightly browned. Remove blondies from oven and place them on a wire rack to cool. Once cooled, cut into squares and serve.