Sift the flour into a mixing bowl and add the baking powder, baking soda, and salt.

In another mixing bowl, use a hand whisk or stand mixer on a slow setting, and beat the shortening until soft and creamy.

Beat the sugar into the shortening mixture gradually.

Follow by also adding the beaten eggs into the shortening mixture gradually.

Add 1/2 of the flour mixture and 1/2 of the mashed bananas, and mix using a fork. Next add the remaining flour mixture and bananas, mixing again with a fork.

Fold in the chopped walnuts.

Turn into a generously greased and lightly floured baking dish and place the slivered almonds on top.

Place the dish on a rack inside the crockpot. Cover with the lid and slightly prop the lid open to allow any steam to escape.

Cook on high for 4-6 hours, allow to cool for 5-10 minutes.

Decorate with slices of banana and serve, delicious warm or cold!