Step 1

In a medium mixing bowl beat butter and cream cheese with an electric mixer on medium to high speed until combined. Add flour and macadamia nuts. Beat on low speed just until combined. Cover and chill for 30 to 60 minutes or until dough is easy to handle.

Step 2

Preheat oven to 325°F. Shape dough into 24 balls. Press each ball onto the bottom and up the sides of an ungreased 1-3/4-inch muffin cup. Bake for 20 to 25 minutes or until edges are golden. Cool slightly in pan on a wire rack.

Step 3

Meanwhile, for filling, in a medium bowl beat egg yolks with a whisk. Gradually whisk in sweetened condensed milk. Add lime peel, lime juice, and, if desired, food coloring. Stir just until combined (mixture will thicken slightly).

Step 4

Spoon about 1 tablespoon of the filling into each pastry cup. Bake about 10 minutes more or until centers are set. Cool tassies in muffin cups on a wire rack for 10 minutes. Remove tassies from muffin cups. Cool completely on wire rack. Chill for 2 to 3 hours or until completely chilled. If desired, before serving, top tassies with Sweetened Whipped Cream.