Preheat the Oven: Begin by preheating your oven to 180°C (350°F) standard / 160°C (320°F) fan-forced. Grease and line your cake tin with baking or parchment paper, setting the stage for your baking adventure.
Mix Dry Ingredients: In a large bowl, whisk together flour, baking powder, baking soda, and sugar. Add the chopped apples, stirring briefly to ensure they're coated and evenly distributed.
Combine Wet Ingredients: In a separate bowl, whisk eggs, vanilla extract, vegetable oil, and Greek yogurt. This mixture is the secret to the cake's moistness and rich flavor.
Unite the Wet and Dry Mixtures: Gently fold the wet ingredients into the dry, mixing with a wooden spoon just until combined. Pour the batter into your prepared tin, spreading it evenly.
Add the Cinnamon Topping: Mix the cinnamon, sugar, and melted butter until it resembles wet, lumpy sand. Sprinkle this mixture over the cake batter for that extra punch of flavor and texture.
Bake to Perfection: Bake for 30-35 minutes. The cake is ready when a skewer inserted comes out clean, a sign that it's cooked through yet marvelously moist.
Cool and Glaze: Once cooled, whisk together the icing sugar and milk for the glaze, adjusting the consistency as needed. Drizzle over the cake, adding that final touch of sweetness.