Preheat the oven to 350°F. Grease a bundt pan and set aside.
In a large bowl, whisk the flour, baking powder, baking soda, and salt together. Set aside.
Using a hand mixer or a stand mixer fitted with the paddle attachment, cream the butter with the sugar until smooth. Add the yogurt, orange juice, vanilla extract, and orange zest and beat to combine. Add the dry ingredients to the wet ingredients and mix on low speed until just combined.
Transfer the cake batter to the greased bundt pan. Bake for 45-50 minutes, or until a toothpick inserted into the center comes out clean. Allow the cake to cool in the pan for 15 minutes before inverting onto a plate. Cool completely before glazing.
To make the chocolate glaze:
In a microwave safe bowl, combine the chocolate with the butter. Heat in the microwave in 30 second intervals, stopping to stir after each interval, until completely smooth. Add heavy cream, one tablespoon at a time, and stir well until the desired consistency is achieved.