Here's a recipe that my husband invented, and has improved over the years. Brandy may be substituted for whisky....

2-3 med-large sweet potatoes
3/4 cup plain yogurt, peeled, cut into chunks or slices.
1 tart green apple
2 T. brown sugar
? whisky or brandy- enough to "melt" the brown sugar (guessing another couple of Tablespoons
About 1/2 cup pecan halves or pieces.

Microwave sweet potatoes, then mash them and stir the yogurt.
Arrange apple pieces on the bottom of baking or casserole dish.

Mix brown sugar with enough brandy or whiskey to "melt" the brown sugar. Mix in about 1/2 cup pecan pieces or halves. Soak for 15 minutes.

Spoon or pour the sweet potato & yogurt mixture over the apples, then spread the brown-sugar / pecan mixture over the top.

Cover and bake in an oven or heat in a microwave