Step 1

Mix flour with the rest of the dry ingredients in a large mixing bowl.

Step 2

In a medium bowl, combine the egg, buttermilk and cooking oil.  Mix it well, then add it to the dry mixture in a large bowl.

Step 3

Add 1 cup of fresh rhubarb (or thawed frozen rhubarb) and the strawberries to the mixture and stir until moist. Let the muffin batter rest in the bowl for 20 minutes.

Step 4

Set your oven temp at 375F.

Step 5

Line a muffin pan with paper liners or parchment paper liners. Use a 12-muffin pan and fill each spot 3/4 full.

Step 6

Mix the second amount of brown sugar and cinnamon in a small bowl. Mix until it has the consistency of coarse crumbs. Sprinkle this on top of each muffin.

Step 7

Bake muffins in a 375F oven for about 20 minutes. Let the baked muffins stand in the muffin tins for five minutes before cooling on a wire rack. The top of the muffins should be crumbly.