In a large mixer bowl, combine the shortening and brown sugar. Mix well.
Add the buttermilk and eggs and mix again.
Add the flour, salt, baking soda, cinnamon, nutmeg and cloves. Mix on low speed for 2 minutes, scraping the sides of the bowl as needed.
Fold in the raisins and walnuts.
Place about 24 cupcake liners in a cupcake pan. Fill the cups about ½ full with the cake batter.
Bake at 350º Fahrenheit for 15-20 minutes or until the top springs back when you touch it.
Allow the cupcakes to cool completely before frosting.
Make the buttercream:
In a large bowl, beat the butter until almost white in appearance.
Slowly add the confectioners' sugar.
Add the lemon juice and the lemon zest as the confectioners' sugar, mixing constantly.
Add in milk as needed to get a good piping consistency and beat until light and fluffy.
Use a large cake decorating tip (Wilton 1M or 2D) to pipe swirls on the cupcakes.
Store in an airtight container.
Recipe Source: Pillsbury Bake Off CookbookThe calories shown are based on the recipe making 24 cupcakes, with 1 serving being 1 frosted cupcake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**