Preheat oven to 350°F. Line muffin pan with baking cups.

In small bowl, heat milk in the microwave until steaming. Whisk in espresso powder until dissolved. Cool.

In medium bowl, sift together flour, baking powder, baking soda and salt.

In medium bowl, beat butter and sugar with electric mixer until light and fluffy. Add eggs and vanilla; mix well. Add flour mixture alternately with espresso mixture, beating well after each addition. Continue beating one minute. Fill baking cups 2/3 full with batter.

Bake 18-20 minutes or until Cake Tester or toothpick inserted in cupcake comes out clean. Cool cupcakes in pan on cooling grid 5 minutes. Remove from pan; cool completely.

Set a fine mesh strainer inside a small bowl.

In small saucepan, stir together sugar, espresso powder, cornstarch and salt. In medium bowl, whisk together milk, cream and egg yolks. Stir into saucepan. Cook over medium heat, stirring constantly, until mixture thickens and boils. Push through strainer. Cover top of filling directly with plastic wrap. Chill completely.

In small bowl, whisk together espresso powder and milk.

In large bowl, beat shortening and butter with electric mixer until light and fluffy. Alternately add confectioners' sugar, one cup at a time, with milk mixture, scraping sides and bottom of bowl often. Beat until fluffy.

Using tip 22, pipe a ring of espresso icing around the outer edge of the cupcake. Using Bismarck tip #230, fill cupcakes with espresso filling, letting it mound up and fill in the center of the icing ring.