Step 1

Preheat oven to 400 degrees F. Grease a 9-inch square pan with butter and set it aside.

Step 2

In a large bowl, whisk the beaten egg, milk, butter till they are well combined.

Step 3

In another bowl, combine the dry ingredients - flour, salt, sugar, and baking powder.

Step 4

Add the dry ingredients and the apples to the wet ingredients and mix them till they are well combined. Pour the batter into the greased pan.

Step 5

In another bowl combine flour,sugar, and butter to make the crumble topping. Sprinkle this crumble topping evenly over the batter.

Step 6

Place the pan in the preheated oven and bake for 25-30 minutes or until a toothpick inserted in the center of the cake comes out clean.

Step 7

Make the glaze - Combine brown sugar, vanilla extract, and water to make the glaze. Pour the glaze evenly over the cake. Let it harden slightly.

Step 8

Serve the cake warm and store the leftovers in the refrigerator.