For popping kernels, follow instructions on package, or use 12 cups plain popped microwave popcorn (without salt or butter). Also, try substituting other types of dried fruit and nuts for the raisins and peanuts.
In a medium nonstick saucepan, melt 2 tablespoons butter over low heat. Add 1 bag (10 ounces) mini marshmallows; cook, stirring, until melted, 10 to 12 minutes. In a large bowl, combine 12 cups plain unsalted popped popcorn (from 2/3 cup kernels), 1/2 cup unsalted peanuts, and 1/2 cup raisins (be careful not to mix in any un-popped kernels).
Pour melted marshmallows over popcorn mixture, and fold to combine. You will need to work quickly since the sugar in the marshmallows hardens as it cools. Rub a little butter into your hands to prevent sticking, and gently form 12 balls, each about 2 1/2 inches across; place on waxed paper. Let set until cool and firm, about 10 minutes.