Mild milk chocolate allows the triple hit of nutty goodness to come forward in these creamy truffles; bittersweet chocolate would overpower those flavors. To speed up prep, chill the chocolate mixture for 1 hour or until completely set; let stand at room temperature for 30 minutes to soften before scooping.
3 tablespoons hazelnut-chocolate spread (such as Nutella)
Combine the first 6 ingredients in the top of a double boiler. Cook over simmering water until chocolate melts (about 2 minutes), stirring constantly. Spoon mixture into a shallow dish. Let stand at room temperature 6 hours or up to overnight.
Scoop about 1 tablespoon chocolate mixture with a spoon. Dredge in nuts; roll into a ball. Repeat procedure with remaining chocolate mixture and nuts.