Preheat oven to 350 degrees and grease a 9x9 square baking pan.
In a large bowl, mash bananas until only a few lumps remain. Add in applesauce and honey. Stir until combined.
Add in sugar; mix. Slowly mix in eggs, 1 at a time.
In a separate bowl, sift together flour, baking powder, baking soda, salt, and cinnamon. Set aside.
Mix together Greek yogurt, vanilla extract, and milk.
Alternatively mix the dry ingredients and the wet ingredients into the banana mixture, beginning and ending with the dry ingredients.
Once combined, pour mixture into baking pan and bake for 45-55 minutes.
While the coffee cake is baking, combine cinnamon, flour, brown sugar, and orange zest. Cut in butter and mix until the topping looks like coarse crumbs.
At the 10 minute mark, pull the coffee cake out and sprinkle the topping as evenly as possible over the cake. Return to the oven and continue baking for 35-45 minutes, or until a cake tester comes out clean.
If desired sprinkle with powdered sugar and enjoy! Cake can be eaten warm, cold, or at room temperature.