Place egg whites in a large bowl. Meanwhile, line a baking sheet with parchment paper. Trace two 8-in. circles 1 in. apart on paper; invert paper.
Preheat oven to 300°. Add vanilla and cream of tartar to egg whites; beat on medium speed until foamy. Sift 1-1/3 cups sugar and cocoa together twice. Gradually add sugar mixture, 1 tablespoon at a time, beating on high after each addition until sugar is dissolved. Continue beating until stiff glossy peaks form. Gently fold in ground pecans. Spread evenly over circles on prepared pan.
Bake until meringue is set and dry, 45-55 minutes. Turn off oven (do not open oven door); leave meringues in oven 1 hour. Remove from oven; cool completely on baking sheet. Carefully remove one meringue to a serving plate.
In a large bowl, beat cream cheese, butter and remaining 1/3 cup sugar until smooth. In a small bowl, beat cream until soft peaks form; fold into cream cheese mixture. Stir in liqueur.
Spread 1/3 cup fudge ice cream topping over meringue. Top with half of the cream cheese filling. Layer with remaining meringue and remaining filling. Sprinkle with chopped pecans. Warm remaining fudge ice cream topping; drizzle over top. Refrigerate at least 2 hours before serving.