Start by getting everything ready. Heat your oven to 175°C. Take a Bundt pan and butter it generously, making sure you reach all the grooves. Lightly dust it with flour and tap out any excess.
In a large bowl, beat the softened butter and sugar together until the mixture looks pale, light, and fluffy. This should take about three to four minutes and helps give the cake a good texture.
Crack in the eggs one at a time, mixing well after each one. Pause to scrape down the sides of the bowl so everything blends evenly.
In another bowl, combine the flour, baking powder, salt, ginger, cinnamon, and nutmeg. Whisk them together so the spices are evenly spread.
Add the dry ingredients to the butter mixture in two parts. Mix gently and stop as soon as everything comes together. Then fold in the apple butter and grated apple until they are evenly mixed through the batter.
Spoon the batter into the prepared Bundt pan and smooth the top. Place it in the oven and bake for about 55 to 65 minutes. The cake is done when a toothpick inserted into the center comes out clean. Let the cake cool in the pan for 15 minutes, then carefully turn it out onto a wire rack and let it cool completely.
To finish, mix the confectioners’ sugar with milk until you have a smooth, pourable icing. Drizzle it over the cooled cake and let it set before slicing and serving.