In a medium bowl, cut cream cheese and butter into flour with a pastry blender until particles resemble small peas.
Shape into a ball.
Wrap in foil or plastic wrap; refrigerate at least 1 hour.
Divide dough into 2 pieces.
On a lightly floured surface, roll out each piece about 1/8-inch thick.
Cut each into a 6-inch circle, reserving excess dough for trim.
Place 1 circle of dough on an ungreased baking sheet.
Place whole Brie cheese in center of dough; top with other pastry circle.
Pinch pastry edges together to seal.
Preheat oven to 400°F (205°C).
Roll out excess dough.
Cut 1 decorative design with a cookie cutter and about 10 small designs with hors d'oeuvre cutters.
Place large cut-out on top of croute and small cut-outs around side.
Sprinkle with sesame seeds.
Bake for 15 to 17 minutes in preheated oven until golden brown.
Let stand several minutes before cutting into small wedges.