Preheat oven to 350 degrees F. Butter and flour a 10 inch bundt pan.
In a medium sized bowl add the yogurt, oil, vanilla and eggs. Beat well and set aside. In a large bowl whisk together the flour,sugar, baking soda,baking powder and salt. Add the liquid ingredients to the dry and mix with a wooden spoon until just blended.
Mix the remaining ¼ cup of white sugar with the cinnamon and toss with the sliced apples.
Pour half of the batter into the prepared pan. Place the sliced apples on top of the batter in an even layer, pressing down into the batter. Cover with remaining cake batter.
Bake for 45-50 minutes until golden brown on top.
Place pan on cooling rack and allow cake to cool for at least 30 minutes before inverting and removing from pan.
Once cake is cool, mix together the glaze and pour over cake.
Recipe by Chateau Elma at https://www.chateauelma.com/apple-coffee-cake