Prepare a loaf pan with parchment paper. I spray the pan, then cut a strip of parchment paper that goes up and over the wide sides of the pan (to help lift the cake out) You can see this in the photos below.

Preheat oven to 350 degrees F.

In a mixing bowl, beat sugar, butter, and orange zest for 4-5 minutes, until light, scraping down the sides half way through.

Add the eggs one at a time, beat to incorporate.

Add the vanilla extract, beat to incorporate.

Combine the flour, baking powder, and salt in a small bowl. Add half to the batter, beat to mix in.

Add the Orange liqueur, and the rest of the flour mixture. Beat on low until the flour is fully mixed in. Scrape the sides and the bottom of the bowl to make sure you have everything mixed well.

Pour the batter into the pan.

Bake for 45 minutes.

While Cake is baking, prepare the soaking liquid by combining all ingredients into a bowl.

When cake is baked, set the pan on a cooling rack.

Use a fork or skewer to poke holes all over the top of the cake.

Slowly spoon the soaking liquid all over the top. Let it soak in a bit before adding the next spoonful. Poke more holes if needed.

Let it soak in for 15-20 minutes. (or longer)

At this point you can remove the cake from the pan and let cool on the rack. If there is still a visible soaking liquid puddle… poke it… then let it sit a few more minutes.)

When the cake is completely cool, you can ice it.

Mix the icing ingredients in a medium bowl. Add 4 tablespoons of Orange Liqueur (or Orange juice) to the powdered sugar and stir. If it feels too stiff, add another tablespoon of liquid. Add some Zest if you like.

Spoon the icing over the loaf cake. (If some drips off, you can scoop it back on).

Sprinkle Orange zest over the top. Slice and serve.