Crumble cookies into fine crumbs. Add melted butter. Press onto the bottom and sides of a 8-1/2 inch greased pan. Place the pan on an aluminum sheet of paper and press the paper against the sides of the pan. Refrigerate.
In a bowl, beat the cheese, incorporate the sugar and then the eggs, one by one. Add vanilla, sour cream and flour.
Pour a third of the mixture on the crust and sprinkle with cookie pieces. Repeat. Pour in the rest of the batter.
Put the pan into a bigger pan and fill the big pan with hot water up to 1 inch from the rim. Bake at 325°F / 160°C for 50-60 minutes or until the sides of the cake are firm but the center is still a little soft. Pass a knife along the edges of the cake. Let cool for 1 hour. After this time, remove the aluminium paper. Let cool on a cooling grill. Cover the cake and refrigirate it overnight. Before serving, decorate with oreo cookie halves.