Method:

Preheat the oven to 180C and prepare a baking sheet
Sift the flour and corn starch into a large bowl
In a separate bowl, cream the butter and sugar together for 2-3 minutes.
While whisking, add the egg and scrape down the sides as needed.
Add the vanilla essence and combine.
Add the flour mixture and combine until the mixture is well incorporated. Wrap the dough in plastic wrap and allow to chill in the fridge until firm.
Once the dough is chilled, roll it between two layers of parchment paper to avoid sticking and tearing. Use a star cookie cutter and cut out an even number of cookies. Take a star cookie cutter that is one size smaller than the cutter used and cut holes into half the cookies.
Place the whole and cut out cookies on the baking sheet and bake for 12-15 minutes. Remove from the oven and cool completely
Melt the chocolate in the microwave in 30 second intervals, stirring in between.
Spread the chocolate onto a whole cookie, leaving the edges clear of chocolate. Top with the cut-out star cookies, repeat the process until all the cookies are combined.