The butter tart debate is as Canadian as the tarts themselves: Should they be oozy, or firm enough to hold their own once you take a bite? You can adjust a tart recipe. For runnier, silkier tarts, reduce baking time by about 5 minutes and enjoy them slightly warm. For firmer, chewier filling, switch from corn syrup to cane or maple syrup, increase baking time by about 5 minutes, fully cool or refrigerate the tarts, or set them aside for a day. Tart shell tips, pg. 579 in 12,167 Kitchen and Cooking Secrets.