Preheat oven to 350°.
To prepare crust, lightly spoon flour into a dry measuring cup; level with a knife. Combine flour, granulated sugar, and 1/8 teaspoon salt, stirring with a whisk. Combine cheese, butter, and milk in a large bowl; beat with a mixer at medium speed until well-blended. Add flour mixture; beat at low speed just until blended (mixture will be crumbly).
Turn dough out onto a lightly floured surface; knead lightly 3 or 4 times. Divide dough into 24 portions. Place 1 dough portion into each of 24 miniature muffin cups coated with cooking spray. Press dough into bottom and up sides of cups, using lightly floured fingers.
To prepare filling, spoon about 1/2 teaspoon walnuts into each muffin cup. Combine brown sugar and remaining ingredients, stirring well with a whisk; spoon about 2 teaspoons filling over walnuts in each muffin cup.
Bake at 350° for 20 minutes or until crust is lightly browned and filling is puffy. Cool in pans 10 minutes on a wire rack. Run a knife around outside edge of each tassie; remove from pan. Cool completely on wire racks.