Growing up in a Cuban family, I’d go to the bakery with my mom every weekend. We’d grab croquetas and pastelitos but on the rare occasion, we’d grab a slice of a brazo gitano.
Bake at 375° about 15 minutes. While still warm, invert it onto a clean, slightly damp towel that has been dusted with powdered sugar. Carefully peel off the parchment.
Gently unroll the cake and evenly spread the guava filling over the cake, leaving ½-inch around the cake. Reserve about 2 tablespoons of the guava filling for later.
Carefully roll the cake up again with the seam side of the cake face down. Wrap the roll tightly in parchment paper and then plastic wrap. Chill for 1 hour.
Before serving, unwrap the roll. Trim the ends off of the cake so the swirl is visible. Brush the cake with the reserved guava filling then dust with powdered sugar.