Nutty Banana-Butterscotch skillet cake 

2 ½ cups all-purpose flour
½ TB baking powder
1 ts baking soda
¼ ts salt
1 ts ground cinnamon
½ cup shortening
½ cup sour cream
½ cup buttermilk
4 ounces unsalted butter, at room temp
1 cup sugar
2 large eggs + 1 egg yolk
3 very ripe bananas, mashed
½ cup butterscotch chips, optional
½ - ¾ cup of pecans or walnuts, chopped, optional

Preheat oven to 350F. Grease with non-stick spray your cast iron skillet.
In a small bowl, mix all the dry ingredients, set aside.
In the bowl of a mixer, mix the shortening, butter, sour cream, buttermilk, and sugar. Add in the eggs, mix, then add in the eggs, and mix. 
 Then by hand, mix in the mashed bananas.
Doing in batches, add in half the dry mixture to the wet mixture, mix till just combined, then add in the other half of the dry mixture and mix till just combined. Please don’t over mix.
Gently fold in butterscotch chips, if using.
Pour the batter into prepared skillet pan. Top the batter with the chopped nuts.
Bake in oven for about 25-30 minutes.
Look for golden brown edges and non-jiggly middle. You can also use a cake tester to see if cake is done.
My cake was done right at the 25-minute mark.

It’s a delicate cake so it can go from done to overdone in literally a couple minutes.
Remember the cast iron heats up a lot faster and holds the heat better than a metal pan, so this cake bakes up fast.