• Preheat oven to 350 degrees. Lightly spray a 8 x 8" square pan with non-stick spray. Set aside.
• Mix the wet and dry ingredients in separate bowls. For the wet ingredients, whisk together the applesauce, sugar, oil, egg and vanilla. In a separate bowl, combine the flour, baking powder, cinnamon and salt.
• Gradually add the dry ingredients to the wet ingredients a few spoonful's at a time, using a large whisk to combine. Once all ingredients are combined, the batter will be thick and smooth. Pour the batter into the prepared pan. Set aside.

For the streusel topping:

• To a bowl, add the flour, brown sugar, cinnamon and salt. Pour in the melted butter. Using a fork mix together until all ingredients are combined. Mixture will be crumbly and resemble gravel.
• Sprinkle the streusel crumble topping evenly over the top of the batter using your hands. Bake the coffee cake at 350 degrees for 38-42 minutes, or until a toothpick inserted into the center of the cake comes out clean and crumb-free. Remove from the oven to let the cake cool.

For Glaze:

• While the cake cools, mix the glaze. Mix together the powdered sugar and milk in a small bowl. Stir together until smooth and slightly thick. The glaze should coat the back of a spoon. Drizzle the glaze over the top of the cooled cake.
• Slice the cake into squares and enjoy.