15 "Fun size" Milky Way Bars (or 36 miniatures
    or 5 regular size), divided
2 1/2 cups heavy cream, divided
1 cup semisweet chocolate chips
1 teaspoon vanilla extract
Whipped cream for topping, optional

Chop 10 candy bars, yielding about 1 1/3 cups. Combine with 1/2 cup of the cream and chocolate chips in a large heatproof bowl over a pot of simmering water. Cook, stirring occasionally, until mixture is melted and combined. Set bowl aside to cool.

In another bowl combine vanilla extract with remaining 2 cups of cream; beat until stiff peaks form. Fold cream into chocolate mixture. Pour 1/2 of mixture into a 1 1/2-quart freezer-proof bowl.

Coarsely chop 2 candy bars, yielding about 1/3 cup. Sprinkle over mousse. Top with remaining mousse. Freeze until firm, at least 6 hours or overnight.

Thaw slightly at room temperature before serving, about 10 minutes. Chop remaining candy bars, yielding about 1/3 cup. Garnish with whipped cream and chopped candy.