Preheat your oven to 350°F (175°C). Grease an 8-inch springform pan with butter and line the base with parchment paper.

In a large mixing bowl, combine the eggs and sugar, then use an electric mixer to beat them until light and fluffy (about 3-5 minutes).

Sift the all-purpose flour and Pane Degli Angeli or baking powder together in a separate bowl. Gradually mix this into the egg and sugar blend until just combined. Incorporate the softened butter.

Stir in the Greek yogurt until the batter is smooth and creamy.

Chop the whole seedless orange into segments and blend until near-puréed. Mix this into the batter and add vanilla extract if using.

Pour the batter into the prepared springform pan and bake for 50-60 minutes or until a skewer comes out clean.

Let the cake cool in the pan for 15 minutes before carefully removing it.

For the glaze, combine orange juice and sugar in a small saucepan. Simmer over low heat for 3-5 minutes until syrupy, then spoon over the warm cake.

Allow the glazed cake to cool completely on a wire rack before serving.