Here is an easy method from the Family Handyman to turn any drawer in your home into a secret hiding spot.
Start with a deep drawer so the difference in depth won’t be so apparent. Then cut a 1/4″ thick piece of plywood to the dimensions of the drawer, minus 1/16″ in each direction. Glue a couple strips of wood to the sides of the drawer at the depth in which you’d like your secret area to be. Then hot glue something you’d find in the drawer to your false bottom to use as a handle. Glue near an edge and it will be less in the way and less likely to be noticed that it doesn’t move if touched.
If done right most people would not expect there to be additional space under the bottom during normal use, and your stashed goodies can go unnoticed for years to come.