In a large bowl, combine Nutella and light brown sugar, and use a hand mixer to beat on low speed until just combined.
1 cup Nutella, 3/4 cup light brown sugar
Add half and half, heavy cream, vanilla and salt, and beat on low speed until completely combined and smooth.
1 cup half and half, 1 cup heavy cream, 1 teaspoon pure vanilla extract, Large pinch of sea salt
Pour into prepared ice cream maker and let it stir on low speed for 20 minutes. Add chopped brownies and chocolate and let stir for another 2-5 minutes until combined.
1 cup brownies, 1 ounce dark chocolate
Pour into prepared pan (top with another sprinkling of salt, on top if desired) and freeze for at least four hours.