Cakes also don't remain as fresh as brownies for very long (at least, not to my picky taste buds) so what I did as soon as I had baked and frosted this is package it all up (2 squares of frosted cake to a package, wrapped in plastic wrap) and place them in freezer bags to reside in the freezer until the day I left. When I pack for my travels and am bringing baked goods, I pack my carry-on luggage the night before and on top, put in empty amazon shipping boxes. That way I know how much room I have and I put the wrapped brownies and cake directly into the empty boxes right before I leave. The baked goods go directly from the freezer to my carry-on, I zip it up and I'm off to the airport.
16 tablespoons (8 ounces) unsalted butter, softened
1 ½ cups (10.5 ounces) granulated sugar
¾ teaspoon salt
3 large eggs
2 large egg yolks
1 ¼ cups (300 ml) whole milk, room temperature
4 teaspoons vanilla extract
2 ¾ cups (11 ounces) cake flour
2 ½ teaspoons baking powder
1. Place an oven rack in the middle position. Preheat oven to 350⁰F. Line a 9 x 13” baking pan with foil and lightly spray with nonstick cooking spray.
2. In a large bowl, beat the butter, sugar and salt until creamy.
3. Whisk in the eggs and egg yolks, one at a time, until each is incorporated.
4. Whisk in the milk and vanilla.
5. Add the flour and baking powder to the bowl, then whisk gently until combined.
6. Pour the batter into the pan and bake until golden, just firm, and a toothpick inserted into the center comes out clean, 25 to 30 minutes.
7. Set the pan on a wire rack and let the cake cool completely before frosting.