ROSIE'S BAKLAVA ICE-CREAM CAKE

Steps:

• With a sharp knife finely chop almonds and walnuts separately. (Resist the temptation to use a food processor; chopping by hand is the key to the texture of baklava.) In a bowl stir together nuts, sugar, and spices. Put stack of phyllo sheets on a work surface and cover with 2 overlapping sheets of plastic wrap and then a damp kitchen towel. Melt butter and keep warm. (If butter cools, it will be too thick to brush.)
• Preheat oven to 350°F.
• With a pastry brush brush a 17 1/2- x 12 1/2- x 1-inch baking pan with some butter. Cover bottom of pan with a phyllo sheet, keeping remaining sheets covered with plastic wrap and towel, and lightly brush with butter. Layer 7 more phyllo sheets, brushing each sheet with butter, in same manner. Sprinkle nut mixture over buttered phyllo and with your fingers gently spread evenly.
• On a work surface (not on top of nut layer) lightly butter and stack remaining 8 phyllo sheets, making sure top sheet is well-buttered. Transfer phyllo stack to baking pan, putting it on nut layer and pressing to help it adhere to nuts. With a fork prick top phyllo stack all over at 1/4-inch intervals going through to nut layer, to keep it from puffing unevenly. With sharp knife halve baklava crosswise and bake in middle of oven until golden brown, about 30 minutes.
• Make syrup while baklava is baking:
• Halve lemon half. In a 1 1/2-quart saucepan boil water, sugar, and lemon over moderate heat, stirring until sugar is dissolved and liquid is reduced to about 1 1/3 cups, about 10 minutes. Remove pan from heat and stir in honey. Discard lemon and cool syrup to warm.
• Pour warm syrup over hot baklava and cool in pan on a rack 15 to 30 minutes. (Baklava will absorb syrup.) Do not let baklava cool more than 30 minutes before assembling cake or phyllo layers will become too soft to transfer.
• While baklava is cooling, soften ice cream. (We softened ours in a microwave set on defrost, 30% power, 1 1/2 to 2 minutes. Alternatively, you can leave it in the refrigerator - not on the counter -30 minutes).
• Assemble cake:
• Using two 30-inch-long sheets of foil, line a 13- x 9- x 2-inch baking pan, arranging 1 sheet lengthwise and 1 sheet crosswise. With a large metal spatula carefully slide 1 baklava half into pan and top with ice cream, spreading evenly. Slide remaining baklava half over ice cream and wrap cake snugly in foil. Freeze cake at least 6 hours and up to 1 week.
• Just before serving, cut cake into pieces.