Preheat your oven to 350°F (175°C).
Grease and flour a 9-inch round cake pan.
In a mixing bowl, cream together the softened butter and sugar until light and fluffy.
Add the eggs one at a time, mixing well after each addition.
Stir in the orange juice and vanilla extract.
In a separate bowl, whisk together the flour, baking powder, and salt.
Gradually add the dry ingredients to the wet mixture, mixing until just combined.
Fold in the orange zest gently.
Pour the batter into the prepared cake pan.
Bake in the preheated oven for 30-35 minutes, or until a toothpick comes out clean.