Heat oven to 350F. Grease a 9 inch pie or tart pan with butter and reserve.
Pulverize graham crackers and toss with melted stick of butter. (Texture looks and feels like wet sand).
Press cracker crumbs into pan and up the sides. Bake for 15 minutes until golden brown. Cool.
Spread bottom of pan with guava jam. Refrigerate for 15 minutes.
To make filling, whisk by hand condensed milk, passion fruit concentrate, lime juice and zest, salt and egg yolks.
Pour into pan and bake for 35-40 minutes at 300F, until center is set.
Cool overnight or at least 4 hours.
To make meringue: cook 1 cup sugar and water until syrup consistency. Whisk whites and five spice powder until soft peak and slowly add syrup. Add the rest of the sugar and whisk until stiff peaks.
Decorate pie with meringue, sprinkling with extra five spice powder. Serve chilled.