Place all the wet ingredients in a blender and mix. You could also use an immersion blender.
In a medium bowl combine all the dry ingredients with a whisk.
Mix the dry and wet mix until you have a thick batter.
Preheat the oven to 350F. Cut the rhubarb and the strawberries into half-inch pieces.
Grease 9 spaces in a muffin pan with coconut oil.
Add half of the batter to the muffin pan, then place 2-3 pieces of the fruit inside. Add the rest of the batter on top and press some more fruit inside. This method will make sure that the fruit is distributed evenly. You want to make sure the fruit pieces are not too close to the bottom or the sides. You can use any fruit that is leftover to decorate the top.
Bake the muffins for 30-35 minutes in the oven, until a cake tester, comes out clean. Let them cool off completely for about 10 minutes, to firm up.
You can store them on the counter for a few days.