Moist pound cake
Generously grease the bundt cake pan with butter. Be sure to get the butter into every corner of the pan. Put the buttered pan in the refrigerator while you make the batter. (Refrigerating the buttered pan will ensure that the butter coating doesn't move when the batter is poured into the pan).
Preheat the oven to 325 degrees.
In a stand mixer fitted with the paddle attachment, or in a bowl, beat the butter, sugar and orange zest until light and fluffy, around 3-4 minutes.
Add the eggs one at a time. Blend until incorporated. The batter may look a little curdled. This is normal.
Mix all of the dry ingredients together with a whisk (flour, baking powder, baking soda and salt). Add half of the dry ingredients to the batter. Blend on low speed until mostly incorporated.
Add half of the buttermilk and the vanilla. Blend until mostly incorporated.
Add the remainder of the dry ingredients and blend until mostly incorporated.
Add the remaining buttermilk. Blend until mostly incorporated. Remove the bowl from the stand mixer. Finish mixing the batter by hand with a spatula.
Remove the cake pan from the refrigerator. If you're using an intricate cake pan, you will want to flour the pan for extra insurance. Pour the batter into the pan. (See marble variation below for specific instructions).
Bake the cake at 325 degrees for 60 to 65 minutes, or until a toothpick comes out clean.
Allow the cake to cool for 15 minutes before flipping the cake onto a serving plate. Shake the pan from side to side to determine if it has released from the sides of the pan. If not, check again in five minutes.
You'll need 50 grams (1/3 cup) of quality chocolate for the marble variation.
Cut the chocolate into small pieces. Put the chocolate in a bowl and microwave for 30 seconds at a time until the chocolate is mostly melted. Then stir by hand until it has completely melted. Allow the chocolate to cool for 5 minutes. (I added 2 drops of burgundy gel food colouring to the melted Ruby chocolate to enhance the colour of the chocolate in this recipe).
Pour half of the batter into the pan. Then add the cooled chocolate. (Try to keep the chocolate away from the edges of the pan). Then add the rest of the batter.
Use a skewer or a fork handle to swirl the chocolate into the batter. Five to six swirls is enough movement to incorporate the chocolate into the batter and create a nice pattern.