Preheat the oven to 170ºC.
Line a rectangular mold with baking paper, and take out the croissant dough, put it on a lightly floured surface, cut the dough in half, we will see that it presents a punctures to cut it into triangles, close it carefully pinching it with your fingers, without pricking the dough, transfer it to the lined mold.
In a bowl beat the cream cheese with the sugar and egg until all the ingredients are incorporated, let stand five minutes and pour over the dough, then cover with the remaining dough. Melt in the micro the 40 grams of butter or margarine, I used the latter, and add the sugar and ground cinnamon, stir and paint the surface of the dough with this mixture. Bake at 170ºC for 30 minutes. Let temper a little to unmold and cut to the size we want.