Go ahead and use any flavor of ice cream in place of vanilla. Chocolate chip, cookies and cream or cherry are all scrumptious choices.
For spreading ease, let the ice cream soften at room temperature for 15 to 20 minutes. To make it even smoother, place it in a large bowl and stir with a sturdy wooden spoon. One word of caution: Try not to let the ice cream get overly soft or melt.