Combine rolled oat, chopped walnut, sugar, and cinnamon in a small bowl, mix thoroughly with a whisk.
Drizzle the melted coconut oil and maple syrup over the dry mixture, and mix with a fork until thoroughly combined.
Set aside until ready to use.
To make muffins:
Preheat oven to 350°F.
Line 12 cavities of a regular size muffin pan with paper liner or spray with nonstick cooking spray if not using liner.
In a medium bowl, add whole wheat flour, baking soda, baking powder, salt, brown sugar and mix thoroughly with a whisk.
Puree or mash the banana and add it to another medium bowl along with egg, Silk Amondmilk Vanilla Yogurt Alternative, Silk Unsweetened Almondmilk, coconut oil and vanilla extract, mix vigorously with a whisk until smooth.
Add the whole wheat flour mixture to the liquid mixture and fold with a spatula until just combined.
Divide batter equally into the previously prepared muffin pan using a large ice cream scoop.
Top the batter with the streusel.
Bake for 19 minutes until a toothpick inserted in the middle comes out clean.
Remove from oven and let cool on a wire rack for 5-10 minutes.
Remove muffins from the pan and place them on the wire rack to cool completely.
This recipe also makes 6 jumbo muffins, increase baking time to 27 mins.