Caramel Cashew White Chocolate Blondies

unsalted butter (melted)

light brown sugar (packed)

large egg

pure vanilla extract

all purpose flour

baking powder

salt

soft caramel candies (unwrapped and cut into eighths (about 1/2 cup))

roasted salted cashews

white chocolate chips

Ice cream (for serving (optional))

Salted caramel sauce (for serving (optional))