Tormento de Amor - Guava Tart with Bizcocho Topping, Made with Alulosa

Combine flour, salt, and a pinch of alulosa in a bowl. Add chilled butter and work it in with your fingertips until the mixture looks like coarse crumbs. Add cold water one tablespoon at a time until the dough just comes together - do not overwork it. Shape into a disk, wrap in plastic, and refrigerate at least 30 minutes.

Butter and flour 8 individual 4-inch tart pans (or one 9-inch pan). Roll the chilled dough to ⅛-inch thickness on a lightly floured surface. Cut circles slightly larger than your pans. Press gently into the pans, trim the edges, and poke the bottom with a fork. Refrigerate 20 more minutes.

Preheat oven to 350°F. Line tart shells with parchment and fill with pie weights or dried beans. Bake 15-20 minutes until lightly golden. Remove weights and paper. Set aside.

In a small saucepan over low heat, combine guayaba paste, water, alulosa, and lime zest. Stir constantly until the paste melts into a smooth, thick jam, about 5-7 minutes. It should be spreadable but not runny. Let it cool slightly.

In a medium saucepan, warm the milk with half the alulosa and the vanilla over low heat until it just begins to simmer. In a separate bowl, whisk the eggs, remaining alulosa, and flour together until pale and smooth. Pour about one-third of the hot milk into the egg mixture while whisking constantly, then pour everything back into the saucepan. Whisk over medium heat until the cream thickens and just begins to bubble, about 3-4 minutes. Remove from heat. Stir in cinnamon, lime zest, and rum if using. Transfer to a bowl and press plastic wrap directly onto the surface to prevent a skin from forming. Let cool to room temperature.

In a stand mixer or with a hand mixer, beat eggs and alulosa together on high speed for 8-10 minutes until very pale, thick, and tripled in volume. This is the key step - the air you beat in here is what makes the sponge light. Reduce to medium and mix 2 more minutes. Fold in sifted flour gently with a spatula. Carefully fold in melted butter, lime zest, and vanilla. Do not deflate the batter.

Spoon a generous layer of guayaba jam into the bottom of each tart shell. Spoon pastry cream on top, smoothing with the back of the spoon. Immediately spoon the bizcocho batter on top, covering the cream completely. Bake at 350°F for 25-30 minutes until the sponge topping is golden brown and a toothpick comes out clean. The top will crack slightly as it cools - that is exactly right.

Let the tarts cool in the pans for at least 20 minutes before unmolding. Serve at room temperature. They are also excellent cold, straight from the refrigerator on day two.