In a large mixing bowl, beat egg whites until foamy. Add cream of tartar and beat until soft peaks form. Gradually add sugar, a little at a time, and continue beating until very stiff peaks form. Fold in pecans.
Cover 2 baking sheets with parchment paper. Draw an 8-10 inch circle on each paper. Divide and spread meringue over each circle, shaping into flat shells. You can also cut out 2 round circles with scissors.
Bake for 45 minutes. Turn off the oven. Do not remove meringues for another 45 minutes. DO NOT OPEN DOOR. Remove and cool. TIP: Meringues may be left in the oven overnight if you choose).
TO ASSEMBLE:
In a medium mixing bowl, beat cream until very stiff. Fold in chocolate syrup and vanilla.
Spread the meringue layer with half of the chocolate cream. Add a second meringue and cover top with remaining cream. Decorate with chocolate shavings and pecan halves. Freeze at least 6 hours. Remove from the freezer 10 minutes before serving.