Initial construction of the Yum Yum Palace began in late winter/early spring 1974 with the clearing and leveling of the site. Great care was taken to keep as many of the grown trees in place around the building.

To pour the concrete foundation for the massive building, forms were placed and concrete was pumped in with a long boomed pumper truck to reach all of the areas from the clearings around the site. To help the concrete cure properly, the foundation walls were topped with straw in an effort to protect it from freezing.

With the concrete foundation in place the steel framework started going up. The building's basic rectangular box shape was the easy part, but the unique webs of steel at each corner needed to make the round and sloped roofs were much more intricate. The steel framework would eventually be well hidden by the building's decorative elements.
As the steel girder frame was completed, smaller and more intricate steel frames were applied to the round edges. These steel frames would eventually support all the fiberglass pieces which made up the colorful ice cream and candy designs.

At the rear of the restaurant, the kitchen area was constructed of concrete block walls. Once finished the building would look unified with the decorative fiberglass parts in place.
Once the steel framing was complete, the carpenters set to work creating the plywood ceilings and framing out the windows and doors to enclose the structure.

While construction was taking place in the park on the building, the fiberglass decorative elements were being fabricated and painted off site.  
In a studio/warehouse, the columns and other decorative parts were molded in fiberglass then painted. These pictures show Warner LeRoy overseeing the process and choosing the colors and elaborate paint finishes before the crew applied them. The intricate candy color marble swirl finish on the tops of the columns must have been a time consuming process.
The finished product of the candy buttons on the column tops was nothing short of spectacular. To see the hundreds of balls on the columns and see that each was unique gives some idea of the hundreds of man hours that must have been required to paint all the decorative pieces for the entire building.
The spiral bases of the columns were equally colorful. The artists did an amazing job of making the fiberglass look edible.

The column tops and bases were married together and carefully wrapped in plastic for their journey down to the park for installation.
With the ceilings stuccoed and the terrazzo floors completed, the columns were assembled, with the two halves covering the steel I-beams. The two halves were sealed together with the tops of the columns against the ceiling. The bases of the columns were left open for a separate fiberglass ring to be applied later.
Work was taking place all over the building simultaneously. While insulation was going into the ceiling, the porch columns were looking nearly complete.  The seams between the two halves would get a finishing coat of fiberglass filler and then the artists would touch up the paint making them look like they were one solid piece.
With the work progressing on the inside, work began on the elaborate top of the building forming the giant sundaes.  Once again, the fiberglass was fabricated off site and trucked in.  The edge of the roof was trimmed with a decorative trim and a steel arch was placed between the sundae scoops on the front of the building to support the array of cones  and scoops.  Arches were planned for the two sides of the building as well as between the front and back sundaes but were never put in placed though the supports still stick out of the restaurant's roof.
Some of the final pieces to be installed were the twists on the archway.  These were equally as colorful as the rest of the building, each one in its own unique color scheme or "flavor".
As spring turned into summer and the park's July 1st opening day drew near, all the elements started to come together, with all the final details being added to the Yum Yum Palace.
Nothing about the Yum Yum Palace was "regular" work for the crews involved. Creating such a fanciful structure had to have been a once in a lifetime experience and created unexpected challenges not found on most everyday construction projects. Considering the short timeline in which the building was completed, the crew did an amazing job.
The sundaes would have additional decorations applied to the big central vanilla scoops, and the roof edge trim would get dollops of whipped cream applied to the white circles.

Once construction was wrapping up and opening day was close, the landscaping crews arrived to plant grass and new trees and bushes around the building. Warner LeRoy's vision was that the Yum Yum Palace like most of Great Adventure's attractions would be hidden by the trees of "The Enchanted Forest" and then be a breathtaking sight when guests arrived at his larger-than-life creations.