For the shortbreads: In a bowl, cream the butter and sugar. Add the eggs and vanilla and beat until smooth. Add the flour and continue beating until just incorporated.
Shape the dough into 2 balls. Wrap in plastic wrap and freeze 20 minutes or until the dough is firm.
For the caramel: In a saucepan, melt the sugar with the water on medium until it becomes a caramel color liquid, approximately 12 minutes. Add the butter and stir until it's all incorporated. Add the cream and stir until it becomes a thick and rich caramel. Remove from heat. Let cool and reserve in an airtight container.
For the chocolate ganache: Place chocolate and cream in a medium-size microwave-safe bowl. Microwave the chocolate and cream for 2 minutes in 30 second intervals, stirring in between each interval until melted and smooth.
Preheat the oven to 350 degrees F/ 180 degrees C.
Using a rolling pin, roll the dough between 2 sheets parchment paper, to a 1/4 to 1/8-inch thickness. Cook's Note: The dough will be very soft.
Place the rolled out dough in the freezer for about 20 minutes or until the dough is no longer sticky and is manageable.
Using a round cookie cutter, cut the cookies and transfer to a baking sheet covered with parchment paper. For 1/2 of the cookies, using a small round cutter, make a hole in the center.
Bake in the oven for about 12 minutes, until the edge and bottom are a light brown. Remove and let cool.
Spread the chocolate ganache onto the 1/2 of the cookies with no holes. Top with a dollop of the caramel. Cover with a cookie that has a hole. Dust with powdered sugar.