Heat oven to 350 degrees F.
Blend crackers, butter, sugar and cinnamon in food processor. Scrape into 9-inch pie plate. Pat in even layer over bottom and up sides.
Bake in 350 degree F oven for 8 minutes. Cool completely on rack.
Heat cream and espresso powder in small saucepan. Remove from heat. Stir in chocolate and vanilla until smooth. Let cool.
Place ice cream in refrigerator for 30 minutes. Spread half the ice cream in even layer in baked shell. Drizzle with half of sauce. Repeat with remaining ice cream and sauce. Freeze for up to 2 weeks.
Remove from freezer 20 minutes before serving. Serve with whipped cream if desired. Makes 12 servings.