Preheat oven to 350°. In a large bowl, mix the first six ingredients. Brush a 13x9-in. baking pan with some of the butter. Unroll phyllo dough; trim to fit into pan.
Layer six sheets of phyllo in prepared pan, brushing each with butter. Keep remaining phyllo covered with plastic wrap and a damp towel to prevent it from drying out. Sprinkle with a third of the nut mixture. Repeat layers twice. Top with remaining phyllo sheets, brushing each with butter.
Using a sharp knife, cut into 1-1/2-in. diamond shapes. Bake 30-35 minutes or until golden brown.
Meanwhile, in a saucepan, combine water, honey, sugar and cinnamon; bring to a boil. Reduce heat; simmer, uncovered, 10 minutes. Stir in vanilla.
Pour over warm baklava. Cool completely in pan on a wire rack. Cover and let stand for several hours or overnight.
In a microwave, melt chocolate chips and shortening; stir until smooth. Drizzle over baklava; let stand until set.