Ready the oven. If using a standard oven, preheat it to 180 degrees C or 350 degrees F. Or at 160 degrees C or 320 degrees F if using a fan-forced oven.

Using baking or parchment paper, line a greased 8-inch round cake pan.

Place the flour, baking powder, baking soda, salt, and sugar in a large mixing bowl. Then, add the chopped apple and briefly stir.

Whisk the eggs, vanilla, oil, and yogurt in another bowl.

To the dry ingredients, add the wet ingredients and gently stir using a wooden spoon until just mixed.

Into the prepared cake pan, spoon the batter.

Mix the cinnamon, sugar, and butter until lumpy and wet. Sprinkle the cinnamon topping on top of the cake batter.

Bake for 30 – 35 minutes until a skewer inserted in the center of the cake comes out clean.

Once done, take the cake out of the oven and onto a wire rack to cool.

In the meantime, whisk the sugar with 1 tbsp milk until smooth to make the glaze. To thin out the glaze, simply add another extra tbsp of milk.

Over the cooled cake, drizzle the glaze.