Preparation
1. Preheat Oven
Preheat your oven to 350°F. Grease a 9-inch springform pan with baking spray, then line the bottom and sides with parchment paper. Set aside.
2. Mix Dry Ingredients
In a medium bowl, whisk together flour, salt, and nutmeg. Set aside.
3. Cream Butter and Sugars
In a separate large bowl, beat the butter, granulated sugar, brown sugar, and orange zest together until smooth and well combined, about 3–4 minutes. Scrape the bowl as needed.
4. Add Eggs and Vanilla
Beat in the egg and egg yolk until fully incorporated, then mix in the vanilla extract.
5. Combine Wet and Dry
Gradually add the dry ingredients to the wet ingredients, mixing just until combined. The dough will be thick.
6. Press Dough Into Pan
Transfer the dough to the prepared pan. Use plastic wrap on top of the dough to help spread it evenly. Press it firmly into all corners, then discard the plastic wrap.
7. Decorate and Bake
Brush the top of the dough with the beaten egg white. Use a fork to create a crosshatch pattern on top.
8. Bake
Bake for 25–30 minutes, or until the cake is golden and a toothpick inserted into the center comes out clean.
9. Cool
Let the cake rest in the pan for 5 minutes before transferring it to a wire rack to cool completely.