May I ask a corollary? How would I say, "Tonight we (our group) are (is) having (hosting) an Ice Cream Social..."? (That is a party where bowls of ice cream, and other desserts made with ice cream - sundaes, banana splits, floats, etc - only, are served as a theme around which strangers are encouraged to meet others.)
Ce soir, nous avons une soirée des Crème Glacée... ?