Preheat your oven to 350F and lightly grease a bundt pan with non-stick cooking spray.
In a large bowl, combine the cake mix, buttermilk, melted butter, eggs, vanilla, and one tablespoon of orange zest. Using a hand mixer, blend everything together at low speed for about 30 seconds or until everything is evenly combined. Turn your hand mixer up to medium speed and beat for two minutes. Using a spatula, fold in your cranberries and scrape the cake batter into your prepared bundt pan.
Bake in the centre of your preheated oven for 45 – 50 minutes or until a toothpick inserted into the cake comes out clean. Allow the cake to cool in the pan for ten minutes or so then turn out onto a cooling rack to cool to room temperature.
For the glaze, mix together the icing sugar, remaining two teaspoons of orange zest, and three tablespoons of orange juice and stir until combined. If your glaze is a bit thick, add a few more drops of orange juice until it is the right consistency. If it’s a bit too thin, add a bit more icing sugar.
Pour or drizzle the glaze over the cake and enjoy!