1Heat oven to 350°F (325°F for dark or nonstick pans). Place paper baking cup in each of 24 regular-size muffin cups Make and bake cake mix as directed on box for cupcakes, using water oil and eggs. Cool 10 minutes; remove from pans to cooling racks. Cool completely.
2Reserve 1/4 cup of the dulce de leche, In medium bowl, stir together remaining dulce de leche and the whipping cream. Spoon mixture into decorating bag fitted with 1/4-inch (#9) writing tip. Gently push tap of bag into top center of each cupcake: squeeze bag until cupcake expands slightly, being careful not to split cupcake.
3In medium bowl, stir together frosting and reserved 1/4 cup dulce de leche. Frost cupcakes. Top With crushed cookies.
4Spoon melted white candy into resealable food-storage plastic bag; cut off tiny corner of bag. Drizzle melted candy over candy bars to look like mummies; add chocolate chip for eyes. Top each cupcake with 1 mummy.