Wedding Cake with Blackberries and Roses

Preheat oven to 350°F. Grease cake pans and line bottom of each with a round of wax paper. Grease paper and dust pans with flour, knocking out excess. Wet Magi-Cake strips and fasten around each pan.

Whisk together eggs, milk, and vanilla.

Whisk salt into flour in another bowl. Beat butter (it should be room temperature) with sugar in a 5-qt. standing electric mixer on medium speed until light and fluffy, about 5 minutes.

Add flour and egg mixture alternately in 3 batches, ending with egg mixture and beating on low speed just until incorporated.

Divide batter among pans so each is filled to 1 inch from top. (If you have a wall oven or other small oven, see cooks' notes, below.)

Bake in upper and lower thirds of oven, with 12-inch pan on upper rack, 20 minutes. Gently turn pans in place so that part of cake that was toward back of oven now faces front and bake cakes until a tester comes out of each with a few crumbs adhering, 10 to 20 minutes more, depending on cake size.

Transfer each cake as done to a rack to cool. Cool cakes slightly (9-inch and 6-inch cakes for 10 minutes; 12-inch cake for 20 minutes) and invert onto racks, peeling off paper. Turn cakes right side up and cool completely.

Clean pans. Make second batch of batter; bake and cool cakes in same manner.

Work with 12-inch cakes first. Trim top of each with long serrated knife to make level, then cut cakes horizontally in half. Put each 12-inch layer, cut side up, on an 11-inch cardboard round.

Brush cut sides generously with syrup. Stir jam until smooth and spread about 2/3 cup on a 12-inch layer. Invert another 12-inch layer (with cardboard), cut side down, onto jam. Discard top cardboard round and spread about 2 1/2 cups frosting on top.

Sprinkle with 1 layer of blackberries to cover frosting. (If berries are 1 inch or larger, halve them lengthwise.) Slide the third 12-inch layer, syrup side up, onto berries, discarding cardboard, and press gently.

Spread about 1/2 cup jam on layer and invert the last 12-inch layer (with cardboard), cut side down, onto jam, then discard cardboard.

Spoon 2 cups frosting onto 12-inch tier and cover cake with a thin coating. (This is called crumb-coating. It tamps down any loose crumbs to keep them out of the top layer of frosting and fills in any crevices.) Chill 12-inch tier while working on remaining tiers.

Trim and halve 9-inch cakes similarly and put on 8-inch rounds.

Brush cut sides generously with syrup. Assemble and crumb-coat 9-inch tier in same manner (use about 1/3 cup jam and 1 1/4 cups frosting between layers; crumb-coat with about 1 1/2 cups frosting). Chill 9-inch tier.

Repeat procedure to make 6-inch tier (use about 2 1/2 tablespoons jam and about 3/4 cup frosting between layers; crumb-coat with about 3/4 cup frosting) and chill until firm.

Reserve 2 cups frosting for piping.

Place 12-inch tier on cake base (preferably on a cake turntable) and frost. Then frost remaining tiers. Chill frosted tiers (do not stack) at least 4 hours.

Cut 3 straws in half and insert 1 straw piece in center of 12-inch tier all the way to bottom. Insert remaining 5 straw pieces in a circle about 1 1/2 inches from center straw and trim straws level with top of tier. (Straws support tiers.) Carefully put 9-inch tier (still on cardboard) in center of bottom tier.

Cut remaining 2 straws in half and insert into middle tier in similar manner, with 1 straw piece in center and remaining 3 straw pieces in a circle around it. Carefully put 6-inch tier (still on cardboard) on top, in center of middle tier.

Fill in any gaps between tiers and any imperfections with frosting and transfer the remainder to pastry bag fitted with 3/16-inch tip. Pipe a decorative border around the bottom edge of each tier. Save remaining frosting for touch-ups—just in case.

Cake should come to room temperature before serving (it may stand at cool room temperature about 6 hours).

Garnish cake with roses and serve slices with blackberries.

·Cake layers may be baked and frozen, wrapped well in foil and sealed in plastic bags, up to a month ahead. Thaw wrapped layers a day before assembling the cake.·If you can't fit the entire assembled cake on its base into your refrigerator, a good place to stop is after assembling and crumb-coating the 3 tiers but before stacking them together. Go to that point 1 day ahead and keep the tiers chilled. Cover each loosely with plastic wrap once the frosting is set. (No smelly things in the fridge, please!) After frosting the tiers, chill them overnight.·Some of our ovens are wall ovens, which tend to be small (ours are about 19 inches wide, 15 inches high, and 17 1/2 inches deep). We found that the cakes cooked more evenly when we cooked the 12-inch cake alone on the middle rack, then the 6-inch and 9-inch together on the middle rack. If you do this, fill all the pans at the same time but leave the 2 smaller cakes at room temperature while baking the 12-inch.