Make crust with crackers and butter to line bottom of a 9" springform pan. Bake 10 minutes at 350 degrees. Set aside to cool. Turn oven to 325 degrees. To make filling, use electric mixer to cream cheese, eggs, and 1/4 cup sour cream until fluffy. Add lemon juice, grated onion, Old Bay, Tabasco, and pepper to the mixture. Fold in crab meat. Mix well. Pour into cooled crust. Bake 50 minutes at 325 degrees until cake is set. Remove from oven. Run knife around edge of cake, loosening it from side of pan. Cool on wire rack. Remove sides of pan. Spread the cake with 1/2 cup sour cream.
» This cake is a versatile dish. Serve it warm for brunch to six people. When cold, serve it with crackers as a canape to 12 or more.