In a large bowl, add in sugar and orange zest. Using your fingers, combine them to release all of the orange oils and fragrances. Do this for a minute. Then add in the flour, baking soda, baking powder, cornstarch, and salt. Mix together.
2 cups all-purpose flour, 1/2 tsp baking soda, 1 1/2 tsps baking powder, 1/2 tsp salt, 1 1/2 tbsp orange zest, 1 cup white sugar, 2 tsp cornstarch
Add in about 1/3 of the butter. Mix on low, and keep adding in the butter until a crumbly texture forms. The key to a tender cake is mixing as little as possible, so only mix until just combined!
3/4 cups unsalted butter
Add the eggs in one at a time, mixing in between each addition. Then, add in the vanilla. On low speed, continue mixing until just combined. Then, add in the orange juice and keep mixing. Make sure to scrap the sides of your bowl too.
1/4 cup orange juice, 3 eggs, 1 tbsp vanilla
Add in the oil, and keep mixing. Then mix in the milk, making sure it’s well incorporated. The batter will be smooth. If it is clumpy, this means your wet ingredients weren’t at room temperature before beginning.
1/4 cup milk, 3 tbsp oil
In the bowl with the cranberries, add 1 tbsp of flour and gently toss around until evenly coated. The light coating of flour will absorb any extra liquid it may have before adding it into the mixing bowl.
2 cups cranberries
Add the cranberries and mix in a few times.
Transfer into the prepared 9x5 pan and spread evenly. Top with extra cranberries if desired.
Bake the cake for 55-75 minutes. The cake is ready when a toothpick comes out clean. I would start checking after 50 minutes as every oven differs! Mine took about 65 minutes.