Stir together the flour, baking powder, and baking soda in a medium mixing bowl. Cut in shortening until the mixture resembles coarse crumbs.
Layer in a 1-quart glass jar or canister the following ingredients: half of the cereal, flour mixture, brown sugar, remaining cereal, and coconut. Tap jar gently on the counter to settle each layer before adding the next. Cover jar.
Store at room temperature up to 1 month. Or, attach baking directions and give as a gift.
Heat oven to 375 degrees F. Empty contents of jar into a large mixing bowl. Stir in egg, milk, and vanilla until combined. Drop by rounded teaspoons 2 inches apart onto an ungreased cookie sheet. Bake for 8 to 9 minutes or until edges are golden brown. Cool on cookie sheet for 1 minute. Transfer to wire racks and cool.