Preheat the oven to 350℉. Grease a 12x16-inch baking sheet with cooking spray, oil, or butter, then line it with parchment paper, pressing down to create a smooth and seamless surface. Grease the parchment paper and set aside.

In a medium bowl, sift together the flour, baking powder, and salt.

In a separate medium bowl, mix together the egg whites and ¼ cup of granulated sugar over medium speed using a hand mixer or stand mixer, until the mixture forms soft peaks, about 4-5 minutes. Transfer the whipped egg whites into a separate bowl and set aside.

In a large bowl, mix together the egg yolks and remaining ½ cup sugar until just combined. Add the oil, milk, and vanilla extract. Mix on medium speed until the mixture is light and frothy.

Pour in ½ of the egg white mixture and mix on low speed just until combined, about a minute. Repeat with the remaining egg whites.

Gently fold the flour mixture into the egg mixture ⅓ cup at a time using a rubber spatula until it forms a smooth cake batter, making sure not to overmix.

Pour the batter onto the prepared baking sheet and spread it in an even layer, making sure to cover the entire baking sheet. Bake for 7-10 minutes, just until the cake springs back when lightly pressed and an inserted toothpick comes out clean. Do not overbake.

Place a piece of parchment paper larger than the cake or a kitchen towel flat on the counter. Dust it with powdered sugar.

When the cake comes out of the oven, quickly run a knife around the edges to loosen it from the pan. Immediately invert it onto the dusted parchment paper or kitchen towel and remove and discard the parchment paper that was on the bottom of the cake.

Starting with the narrow end, roll the cake up tightly with the parchment paper or towel, being careful not to tear it. Cool the cake completely at room temperature rolled up in the parchment paper or towel, about 2 hours.

Once cooled, slowly unroll the cake. Spread 1 ½ - 2 cups of strawberry jelly, jam, or preserves over the entire cake. Gently roll the cake back up tightly without the parchment paper or towel.

Spread the remaining strawberry jelly over the top and sides of the niño envuelto. Sprinkle the outside with shredded coconut until fully covered.

Optional: Cut off a ½-inch slice from both ends to give you a more uniform look.

Transfer it to a serving tray and slice into 1 inch pieces. Serve immediately.