Salted Chocolate Nutella Fudge

I took this recipe to a potluck tonight where there were about 30 people. No fudge was left at the end of the evening.

1 (14-ounce) can sweetened condensed milk
8 ozs (1 1/4 c) high-quality bittersweet (60% cacao) chocolate chips
1 cup Nutella
3 Tbsp unsalted butter, cut into 1/2" pieces
1/2 to 1 tsp sea salt

Line bottom and sides of a 9" baking pan with waxed paper, leaving a 2" overlap. It helps to dot the center bottom of the pan with a bit of butter to help the waxed paper stick.

In a medium glass bowl, stir together sweetened condensed milk, bittersweet chocolate chips, Nutella and butter. Cook over gently simmering water, or in the microwave, until the chocolate chips are melted and the mixture is smooth, about 5 minutes. Scrape the mixture into the prepared pan, spread the top smooth with a spatula, and sprinkle with sea salt. Refrigerate until firm, at least 2 hours.

Using paper, lift fudge out of pan, then peel off waxed paper. Dip a knife into hot water, dry it, and cut the fudge into squares, dipping and drying knife as needed. Store fudge refrigerated in an airtight container. Makes 64 pieces.