Add the vinegar to the almond milk and set aside to curdle (you’re making buttermilk).
Position the rack in the center of the oven and preheat the oven to 350°F. Spray the muffin tins with nonstick baking spray or line with paper muffin cups.
In a large bowl, whisk together the all-purpose flour, whole wheat flour, baking powder, cinnamon, salt; set aside.
In another bowl, place the buttermilk, applesauce, canola oil, sugar, marmalade, lemon zest, vanilla, and Cointreau. Whisk together until combined.
Gently fold the wet ingredients into the dry ingredients. Scrape down the sides of the bowl as folding to combine the ingredients; make sure to not over mix.
In a small bowl, mix together the streusel topping; set aside.
Fill the prepared tins three-quarters full. Sprinkle the streusel topping on top of each muffin. Bake for 17-20 minutes, or until a toothpick inserted into the center of one muffin comes out with a crumb or two attached.
Set the pan on a wire rack to cool for 10 minutes.