1Heat oven to 350°F. (325°F for dark or nonstick pan). Spray bottom only of 13x9-inch pan with cooking spray. Make and bake cake mix as directed on box using water, oil and eggs. Cool completely.
2Crumble cake into large bowl. Add frosting and liqueur; mix well. Roll mixture into 1 1/2-inch bails; place on cookie sheet. In 1-quart heavy saucepan, melt candy coating over low heat, stirring occasionally. Stir in 3 teaspoons of the shortening until smooth.
3Place sheet of waxed paper on work surface. To coat each truffle, place on 2-pronged meat fork; hold over saucepan of chocolate. Spoon chocolate over truffle, making sure to cover cake particles completely. Let excess chocolate drip back into pan. Using tip of knife, slide coated truffle onto paper. Let stand at room temperature until set, about 15 minutes.
4In small microwavable bowl, microwave baking chips and remaining 1/2 teaspoon shortening on High 30 to 60 seconds or until mixture is smooth. Drizzle over truffles. Let stand until set.