Preheat oven to 350ºF. Line muffin pan with baking cups.
In small bowl, heat milk in the microwave until steaming. Add instant coffee and whisk until dissolved. Add 1/2 cup Irish cream liqueur. Cool slightly.
In large bowl, sift together flour, baking powder, baking soda and salt.
In large bowl, beat butter and sugar with electric mixer until light and fluffy. Add eggs and vanilla; mix well. Add flour mixture alternately with coffee mixture, beating well after each addition. Beat until just combined. Fill baking cups 2/3 full with batter.
Bake 18-20 minutes or until toothpick inserted in cupcake comes out clean. Cool cupcakes in pan on cooling grid 5 minutes. Remove from pan; cool completely. Poke tops of cupcakes 3-4 times with fork. Spoon 1 teaspoon Irish cream liqueur over each cupcake.
In small bowl, heat Irish cream liqueur in the microwave until steaming. Add instant coffee and whisk until dissolved. Let cool slightly.
In large bowl, beat shortening and butter with electric mixer until light and fluffy. Alternately add confectioners? sugar, one cup at a time, with coffee mixture, scraping sides and bottom of bowl often. Beat until fluffy.
Pipe a 1M swirl of icing on each cupcake. Sprinkle with Gold Pearlized Sugar.