If some one eats cake during a meal that hamotzei was made does a bracha have to be made? Does it matter when the cake is being eaten?
If all three conditions of pas haba be’kisnin are met: the cake is sweet, filled with a filling, and crispy, a berachah should certainly be made on the cake. When only one or two of the three conditions are met, the Mishnah Berurah (Biur Halachah 168, c.v. te’unin) rules that for cake with a filling one should (and at least can) make a berachah, but for cake that is sweet one should not.
Some write that for today’s cakes, which are baked from a soft batter, one should always make a berachah on the cake, though others dispute it (the opinions are quoted in Vezos Haberachah). If you don’t have a specific custom one way or the other, the general custom is not to make a berachah on regular cakes (without a filling), even if eaten for dessert.