For the cupcakes: Preheat oven to 350 degrees and line cupcake pans with 18 paper baking cups. In a medium mixing bowl stir together flour, baking soda, baking powder, salt, cinnamon, cloves, and nutmeg, set aside.
In a large mixing bowl with an electric mixer on medium speed cream butter, shortening, and sugar until fluffy. Beat in eggs. Beat in sour cream and water. On low speed gradually add flour mixture and beat until smooth. Stir in nuts.
Divide batter between baking cups. Bake until a toothpick inserted into the center comes out clean, about 20 minutes. Let cupcakes cool in pans for 10 minutes. Transfer cupcakes to cooling racks to cool completely.
For the frosting: In a medium mixing bowl with an electric mixer on medium speed, beat cream cheese and butter until smooth. Gradually add powdered sugar. Add vanilla and maple syrup and beat until smooth and creamy.
Frost cooled cupcakes with frosting and top each cupcake with a pecan half.