To make it...
Turn on broiler. Toss the apples with the lemon juice, butter, and all but 2 tablespoons of the sugar. (Can be made to this point up to 1 day ahead. Store in a resealable plastic bag and refrigerate.) Arrange on a baking sheet in a single layer. Broil the apples about 8 inches from the heat for 8 to 10 minutes or until tender. Sprinkle with the remaining 2 tablespoons of sugar and broil until melted. Meanwhile, heat the rum or maple syrup in a small saucepan over low heat. Serve the apples warm with vanilla ice cream. Drizzle with the warm rum or syrup.
To fake it...and save 20 minutes
Heat broiler. Dump the apples from two 12-ounce packages scalloped apples onto a broiler pan or baking sheet. Toss with the grated zest from 1 lemon. Spread the apples in a single layer and broil about 8 inches from the heat for 5 minutes or until bubbly. Meanwhile, heat 1/3 cup rum or 1/2 cup maple syrup in a small saucepan over low heat. Serve the apples warm with vanilla ice cream. Drizzle with the rum or syrup.