Preheat oven to 180°C (350°F). Grease and line an 8-inch round cake pan.
In a large bowl, mix flour, baking powder, baking soda, salt, and sugar. Stir in chopped apples.
In another bowl, whisk eggs, vanilla, oil, and yogurt until combined.
Add wet ingredients to dry ingredients and mix gently until just combined. Do not overmix.
Pour batter into prepared pan.
Mix sugar, cinnamon, and melted butter for topping. Sprinkle evenly over batter.
Bake for 30–35 minutes or until a skewer comes out clean.
Let cake cool completely on a wire rack.
Mix powdered sugar with milk to form glaze and drizzle over cake.
Slice and enjoy your Cinnamon Apple Cake.