Try different fruits and syrups or glazes--raspberries with chocolate sauce, for instance, or apricots with blueberry preserves, heated just until they're liquefied. Use fruits that aren't too juicy, or else the crust will be soggy. Prep and Cook Time: about 45 minutes, plus at least 2 hours chilling time. Notes: When making the caramel, it helps to use a regular stainless steel or other light-colored saucepan; the paler background lets you see the true color of the caramel as it darkens. The sauce may be made up to a week ahead and kept chilled, covered in plastic wrap. Leftovers are great on ice cream.
1/2 cup granulated sugar
1/2 cup heavy cream
2 tablespoons dark rum
1/2 pound chilled puff pastry
4 firm-ripe bananas
Egg wash (1 egg whisked with 2 tbsp. water)
3 tablespoons light brown sugar
How to Make It
Preheat oven to 375°. Put sugar with 1/4 cup water in a small, deep, heavy saucepan and, without stirring, bring to a boil over medium-high heat. Using a pastry brush dipped in water, brush down sides of pan to dissolve any sugar granules. When sugar has dissolved and begins to darken, 6 to 8 minutes, tilt and swirl it to cook evenly. Cook, swirling pan occasionally, until sugar is a deep reddish brown, about 2 minutes more. Remove from heat and whisk in about 1 tbsp. of cream (sauce will foam up). Slowly whisk in the rest. Whisk in rum, let cool to room temperature, and chill at least 2 hours to thicken.
Meanwhile, on a floured work surface and with a floured rolling pin, roll pastry sheet out to a 10- by 14-in. rectangle. Cut pastry in half to form two 10- by 7-in. rectangles and place halves on a large, rimless baking sheet. Lightly prick pastry halves with a fork, leaving a 1/2-in.-wide border.
Peel bananas, cut into 1/4-in.-thick slices, and arrange on pastry. Brush borders with egg wash and sprinkle tarts all over with brown sugar.
Bake tarts on bottom rack of oven 15 to 17 minutes, or until crusts are medium golden brown (lift edges of tarts to check doneness of undersides). Let cool slightly and drizzle generously with caramel sauce. Serve tarts warm or cool, each cut into 4 to 6 pieces.