Preheat oven to 350F. Line & grease a 9 x 9 baking dish.
In a small mixing bowl, combine the crumb topping ingredients until you have a crumbly mixture. Set aside.
In a large mixing bowl, mix together the sugar, butter, eggs, yogurt or sour cream, milk, chai, espresso, and vanilla until smooth. I like to use an electric hand mixer, but a whisk works as well. Mix in the flour, baking powder, cinnamon, and salt until a batter forms—be careful not to over mix!
Transfer the batter to the baking dish. Sprinkle the crumb topping evenly on top. Transfer to the oven and bake for 45-50 mins, or until it passes the toothpick test. Let this cool on a wire rack for 20 minutes.
In the meantime, whisk together the maple icing. Once the coffee cake has cooled and set, drizzle it with the icing, slice, and enjoy!
