Chocolate Nut Fudge

1 (12 ounce) bag semisweet chocolate chips

½ cup sour cream

¾ cup confectioners sugar

¼ teaspoon salt

2 cups finely crushed vanilla wafer crumbs

½ cup broken walnuts

Line an 8x8-inch baking pan with aluminum foil.

Melt chocolate chips in a large, heavy pan over low heat, stirring constantly to avoid scorching, until melted and smooth, about 10 minutes. Stir sour cream, confectioners sugar, and salt into the chocolate. Mix the vanilla wafer crumbs into the chocolate mixture and stir in broken walnut pieces. Spread fudge into the prepared pan, refrigerate until firm, and cut into squares.