It is not advisable to set the counter top with adhesive caulk; the top must be securely fastened to the base unit by using appropriate length wood screws. Most cabinet manufacturers provide corner blocks within the cabinet for attaching the counter top to the cabinet base, and pilot holes predrilled through the corner blocks into the underside of the top. Be careful that you do not drill too far into the top.
Some manufacturers of cabinets and appliances take into consideration expansion and contractions by slotting the screw holes. Where a manufacturer has not made such allowances, you should use an undersized screw with a washer or counter sink pilot holes are drilled at the extreme ends of the slots and the block has expanded, you negate the advantage of the slots.
A suggested way to make this allowance in attaching wood parts is to counter sink the pilot holes where the wood part attaches to block, or make the pilot holes oversized using a flat head screw and a washer.
If you were installing a back splash along with the counter top, it would be advisable to attach it at this time. The back splash is usually attached to the surface, not to the back edge that would be against the wall.
In many areas post-form counter tops are popular. Butcher Block does not come in this shape, but many fabricators will use a hand router to round the front edge of the block to conform to the front edge of the post-form top. When this cut is made, sand smooth and finish with “Good Stuff” Urethane Gel clear protective finish.