Melt butter in
saucepan. Stir in crumbs, sugar and cocoa. Mix well. Press into
bottom of ungreased 9-inch springform pan. Bake in 350 F oven for 10 minutes.
Beat cream cheese
and sugar at low speed until blended. Add eggs, one at a time,
beating slowly after each addition. Mix in concentrated orange juice.
chips in saucepan over low heat. Stir to hasten melting. Add to
cheese mixture. Add flavorings. Pour into crumb-lined pan. Bake in
325 F oven for 70 minutes until top feels firm and dry. Cake will
quiver if pan is shaken slightly. Cool at room temperature, then
chill several hours or overnight before serving.