Pumpkin-butterscotch crumb cake 
from vanillasugarblog.com

2 cups all-purpose flour
2 ts baking powder
3/4 cup sugar
¾ cup of plain greek yogurt (or sour cream)
½ can (or 7.5 ounces) plain pumpkin puree
2 large eggs
1/3 cup vegetable oil
a couple dashes of pumpkin spice
a couple dashes of cinnamon
giant pinch of salt

crumb topping:
1 stick of butter (8 ounces) melted & cooled
½ cup sugar
¼ cup dark brown sugar, packed
1 cup flour
a few dashes of pumpkin pie spice
½ ts salt
¾ cup pecans, small chop (or you could use walnuts)
¼ cup (or more if you like) butterscotch chips

Preheat oven to 350F.
Sift flour, baking powder, and spices into a bowl; add in the sugar and mix.
In a separate bowl whisk greek yogurt, eggs, pumpkin, and oil together.

Stir in the dry ingredients until just combined. Lumps are good, do not overmix.

Spread batter into 9 or 10 inch cake pan.

Make the crumb mixture by combining all ingredients in a bowl, mix well, and then add in the butter;  mix.

Using your hand, make medium clumps and place on top of cake batter.

Bake for 35-40 minutes or until toothpick comes out clean.

Please let this set up and cool at least an hour before slicing.

You could try using this batter in muffin tins.  Just reduce and/or watch the baking times.