Heat oven to 425° with a rack in bottom position and another in center. Cut each puff pastry sheet into a 9 x 9-inch square. Place both on a parchment-lined baking sheet. With a fork, prick all over.Advertisement
For each pastry square, fold in top right corner 1 inch. Fold top edge over folded corner, then fold in top left corner. Repeat on all sides. Bake on bottom rack for 10 minutes, until puffed and very lightly golden.
Meanwhile, slice plums into 1/4-inch-thick wedges. Arrange plums in center of each parbaked puff pastry in a circular pattern. Lightly brush both tarts all over with agave. Sprinkle with a pinch of pepper. Bake 8 minutes, until golden.
Drizzle with honey and sprinkle with salt. Let cool. Serve with Plum-Coconut Mocktail, if desired. Makes 2 tarts.