This is a special dessert that can be made any time of the year (I usually make them around the holidays), as they make a very pretty presentation that will impress, and everyone will love them!  Recipeis below.
1/2 C. Butter, softened 
1 C. Sugar (I use dark brown)     
2 C. cooked & mashed Sweet Potatoes
2 large Eggs                                    
1/3 C. Buttermilk (you can sub 1 T. plain Greek yogurt & milk)
1 1/4 C. All purpose Flour                    
1 t. Baking Soda                            
1/2 C. chopped pecans, toasted or plain
1 t. Vanilla Extract                          
Caramel sauce (I use the Mexican “Cajeta” or “Dulce de Leche”)
1/2 t. Salt
1/2 t. Cinnamon
1/2 t. grd. Ginger                          
(optional:  Whipped Cream or Vanilla Ice Cream)
1.  Beat butter & sugar at med. speed with mixer til smooth.  Add eggs, 1 at a time, blending til blended after each addition.
2.  Combine flour & baking soda.  Gradually add half of flour mixture to butter mixture, beating at low speed til blended.  Add remaining half of flour mixture; beat til blended.  Add vanilla & salt & spices, Sweet Potatoes & Buttermilk, beating at med. speed til smooth.  Spoon batter into 12 muffin cups (coated with
oil spray), filling only half full.  
3.  Bake at 350 for 20-25 min. or til wooden pick inserted in center comes out clean.  Cool in pan on wire rack 5 min.  Gently remove warm cakes, placing upside down on plates.  Sprinkle with Pecans & drizzle with Caramel sauce.  Try to eat while still warm. 
Caramel Sauce:  Melt 2 T. Butter in thick pot & melt.  Add 1 C. Cajeta and 1 T. water. (I like to add 1/2 t. of instant coffee granules, too) Stir.  Heat on low till smooth.
Serve warm on warm cakes. You can top with whipped cream or ice cream, too, but it is excellent without.