My Blueberry Muffin Variations (Raspberry and Banana)

I have been a much happier person in the last few weeks thanks to Smitten Kitchen's blueberry muffin recipe. It is so good I have tried some variations that I want to write down so that I don't forget.  

INGREDIENTS for Raspberry Variation:

-70 grams of butter.
-1/2 cup of sugar (100 grams)
-The grated zest of a lemon.
-3/4 cup of yoghurt or kefir.
-1 egg
-1+1/2 tsp of baking powder.
-1/4 tsp of baking soda.
-1/4 tsp of salt.

-1+1/2 cup of flour.
-1+1/2 cup of frozen raspberries  (25o0 grams)

INGREDIENTS for Banana Variation:

-70 grams of butter.
-70 grams of white sugar (a lot less sugar!)
-3/4 cup of yoghurt or kefir.
-1 egg.
-1+1/2 tsp of baking powder.
-1/4 tsp of baking soda.
-1/4 tsp of salt.

-1+1/2 cup of flour.
-4 bananas as old as you can  (25o0 grams)