In a large bowl, cream sugar and shortening until light and fluffy. Beat in egg, then milk and vanilla. Combine the flour, baking soda, baking powder and salt; add to creamed mixture just until combined. Fold in chocolate chips.
Spoon about 1 tablespoon of batter into each greased or paper-lined mini-muffin cup. Bake at 375° until a toothpick inserted in the center comes out clean, 10-13 minutes. Cool in pans for 5 minutes before removing to wire racks. Serve warm.