Peel the sweet potato and cut in cubes. Steam or cook the sweet potato until cooked through.
Preheat the oven on 180 degrees Celsius or 356 degrees Fahrenheit.
And grease the baking pan with oil or butter.
Caramelized Pecans
Add the powdered sugar and spices to a bowl. Add a tablespoon of water and mix everything. Then add the pecans and mix until all pecans are coated. If the powdered sugar mixture is still too crumbly, you can add a teaspoon of water.
Divide the pecans in an oven dish. Roast them in the oven for about 15 minutes or until caramelized and brown.
Mixing
Break the egg in the bowl. Use a whisk to whip up the egg until pale yellow and foamy. Then add the sugar spoon by spoon and pour in the olive oil, both while whisking. Then add the zest of an orange, milk, cinnamon and vanilla.
Mash the cooked sweet potato into a puree.
Mix the mashed potato with a third of the egg mixture. Then fold in the rest of the mixture. Try to keep the batter as light/fluffy as possible.
Use a five sieve to add the flour and baking powder to the batter. When everything is mixed, you can divide half of the batter into the bundt cake baking pan (unless you have a baking pan that fits 12 mini bundt cakes)
Baking
Bake the bundt cakes for 18 minutes in the preheated oven. Repeat until you are out of batter.
Glaze
Mix the powdered sugar first with half of the espresso. You want to have a glaze that it not too runny, but thick enough to stay on its place on the pastry. So add more espresso (little by little) until you reached that consistency. If the glaze is still too thick, you can add a little bit of water. It is easy to add too much water, since just a little bit of moisture is needed to make the glaze. So be careful when adding the moisture, and stir well!
Finishing Touches
Dip the cooled down cakes in the glaze and top with the pecans!