Brazo gitano

Preparation

1. In a medium saucepan over medium-high heat, add the guava paste and ¾ cup of water. Cook, stirring occasionally, until the guava paste is smooth and thick, about 8 minutes. Set aside to cool. You should have about 2 ¼ cups.
   In a separate small saucepan over medium-high heat, add ⅓ cup sugar and ⅓ cup water. When it begins to boil, stir occasionally until the sugar dissolves. Transfer the mixture to a small bowl and add the vanilla. Leave to cool.
2. Preheat the oven to 220°C. In a medium bowl, using an electric mixer, beat the egg whites until stiff peaks form, then set aside. In another medium bowl, mix the remaining egg yolks, ⅔ cup sugar and salt until the yolks turn pale yellow. Add the flour and stir until well combined.
3. Using a spatula, fold ⅓ of the egg whites into the egg yolk mixture until combined. Gently fold in the remaining egg whites until fully incorporated. The mixture should be light and fluffy. Spread the batter evenly onto a 28 cm x 40 cm baking tray lined with parchment paper. Bake until the sponge cake is lightly golden and springs back when gently pressed with your finger, about 10–15 minutes.
4. Turn the sponge cake out onto a paper towel or sheet of parchment paper dusted with powdered sugar.
5. Remove and discard the top layer of parchment paper. Trim any uneven edges with a knife. Using a pastry brush, apply the reserved vanilla syrup over the cake until absorbed. Starting from the long side, roll the sponge cake jelly-roll style. Let it rest seam-side down until cool.
6. Gently unroll the sponge cake. Using a spatula, spread the reserved guava filling evenly over the surface, leaving a 2.5 cm border around the edges. Reserve one tablespoon of guava filling. Starting from the long side, gently but firmly roll the sponge cake again, jelly-roll style. Place it seam-side down on a serving platter.
7. Spread a thin layer of the reserved guava mixture over the outside of the cake and refrigerate until ready to serve. Dust with powdered sugar before serving.