Preheat oven to 375 degrees.  Line 12-cup muffin pan with muffin liners.  To make the topping, combine the almonds, oats, flour and cinnamon.  Stir in the maple syrup and melted butter.  Set aside. 

In a large bowl, mix together the flours, baking powder, baking soda, salt and cinnamon.  Add in the chopped rhubarb and stir to coat.  In a separate medium bowl, whisk the eggs with the greek yogurt, maple syrup, canola oil, vanilla and almond extract.  Lightly stir the wet mixture into the dry mixture and mix until the batter just comes together, do not overmix.  Spoon the batter into each muffin cup.  The batter should fill the entire cup and reach a bit higher than the top of the cup.  Top the muffins evenly with the almond topping and gently press the mixture into the batter so it will adhere a little better. Bake the muffins for about 20-25 minutes, until they are golden brown, and a toothpick inserted in the center comes out clean. Let the muffins cool in the pan for about 5 to 10 minutes.