Preheat the oven to 350°F.

Line a rimmed 13x15-inch baking sheet with parchment paper and lightly coat with cooking spray.

In a large bowl, whisk the flour, baking powder, and salt together. Set aside.

Beat together the eggs, and sugar.

Add the oil, milk, and vanilla and beat until thoroughly combined.

turn the mixer down to low and gradually beat in the dry ingredients until just combined.

Transfer the batter into the baking sheet.

Place in the oven and bake for 25 minutes or until a knife inserted into the center of the cake comes out clean.

Remove from the oven and let cool in the pan.

Run a knife around the edges of the pan. Invert the cake onto a work surface, leaving the parchment paper stuck to the cake.

Beat the butter and a 1/2 cup of powdered sugar together.

Add the rest of the powdered sugar 1/2 cup at a time, beating well after each addition.

Add the vanilla and milk or water and beat until smooth.

Cover the bowl with a wet dishtowel.

Draw a large egg shape on the parchment paper on top of the cake.

Cut out the shape and place it on top of the cake.

Use a sharp knife to cut out an egg shape. Discard the cake scraps or save for later use.

Crumb coat the cake: Use a spatula to cover the cake with a light coat of frosting. It’s OK if you can see the cake through the frosting. Replace the wet dish towel over the bowl of frosting.

Place the cake in the refrigerator for 30 minutes.

Remove the cooled cake and coat with the rest of the frosting. If the frosting it too stiff, run the spatula under hot water and then use it to frost the cake.

Scrape the jam onto the center of the cake and gently spread it, keeping it in a circle shape.

Cut and serve.