Classic Hot Fudge

1. Combine the chocolate, heavy cream, butter, corn syrup, brown sugar, cocoa powder and salt in a small saucepan over medium heat. Cook, stirring often, until the chocolate is melted and smooth, about 5 minutes. (Do not simmer or the chocolate may scorch and taste bitter; reduce the heat if needed.)
2. Remove from the heat and stir in the vanilla. Let cool slightly. Refrigerate up to 1 week; reheat in a small saucepan over low heat or microwave in 30-second intervals, thinning with more heavy cream if needed.

Peanut Butter

1. Use milk chocolate instead of semisweet along with 1/3 cup creamy peanut butter; increase the heavy cream to 1 cup and the brown sugar to 1/4 cup. Stir in 1/2 cup chopped salted roasted peanuts at the end.

Butterscotch

1. Use half semisweet and half milk chocolate along with 2/3 cup butterscotch chips; increase the butter to 6 tablespoons.

Tropical Raspberry

1. Add 1/3 cup seedless raspberry jam with the chocolate. Replace the butter with coconut oil and omit the corn syrup and brown sugar. Use coconut extract instead of vanilla.

Cherry-Almond

1. Add 1/3 cup cherry jam with the chocolate. Omit the corn syrup and brown sugar. Use 1/2 teaspoon almond extract instead of vanilla.

Spicy Orange

1. Add 1/3 cup orange marmalade and 1/2 teaspoon chipotle chile powder with the chocolate. Omit the corn syrup and brown sugar. Add 1/4 teaspoon orange extract with the vanilla.

Hazelnut-Mocha

1. Use milk chocolate instead of semisweet along with 1/3 cup chocolate-hazelnut spread and 1 tablespoon instant espresso powder. Omit the corn syrup, brown sugar and vanilla. Stir in 2 tablespoons hazelnut liqueur at the end.