Five tiers of dense double-chocolate brownies are glazed with caramel and trimmed with candied pecans for this magnificent cake. Vanilla ice cream is served alongside.
When brownie layers have cooled, unmold by inverting onto cardboard square. Immediately invert them again directly onto corresponding acrylic squares, with exception of 12-inch layer. With 12-inch layer, cut 2 1/4-inch square from center; reserve scraps. Place 12-inch acrylic plate upside down on top of brownie, fitting acrylic square inside cutout square. Invert layer onto acrylic plate. Position long acrylic pole in center of 12-inch layer, and secure to acrylic base plate. Then, using a few reserved scraps, fill in space around hole. Pack scraps densely; with an upward, twisting motion, pull pole out of brownie, making sure new, smaller hole remains intact. Set pole aside.
Mark center of 8- and 6-inch brownie layers by scoring an X from corner to corner with knife. Position 1 1/2-inch round cutter in center of X, and cut out circle; reserve scraps. Center pole of stand will pass through these holes.
Cut center circles out of hardened squares of caramel glaze, using same technique as for brownie layers. Invert onto corresponding tiers, and refrigerate tiers until cake is ready to be stacked.
Hot-glue a 3-inch-wide decorative ribbon around the top edge of each "spacer" tube. Set aside.
At reception site, stack layers on cake table: Place 12-inch layer on table. Fit long tube snugly into 12-inch layer. Slip 4-inch spacer tube onto long pole, and slide it down until it rests on plate. Place the 10-inch brownie tier on long pole, and slide it down until it rests on spacer below. Add 5-inch spacer tube and then 8-inch brownie tier. Stack 6-inch and then 4-inch tiers in the same manner, placing 5-inch spacer tube between each.
Tint the royal icing dark brown. Fit a 12-inch pastry bag with an Ateco number 5 round tip, and fill it with the brown royal icing. Use dots of icing to glue candied pecans side by side on the edges of each acrylic plate, covering the acrylic.
An acrylic pole keeps the tiers aligned; pieces of acrylic tubing slipped over the pole separate the tiers. Use a custom-designed acrylic cake stand to support the brownie tiers.