Heat the oven to 350 degrees F. Grease and flour 2 (8 1/2 by 4 1/2-inch) loaf pans.
Put the candies in a large bowl and mix them up well. Take 2 tablespoons of the flour and toss it with the candies to coat them so they will not sink or stick together. Set aside. Whisk the baking powder and salt into the remaining flour and set aside.
Using a stand mixer with a paddle attachment or a hand held mixer, beat the butter until light and fluffy, about 1 minute. Add the sugar a little at a time scraping down the sides of the bowl once or twice, until the mixture is smooth and fluffy. Add the eggs 1 at a time beating well, then the vanilla. Pour in half the flour mixture and beat on low speed until it is incorporated. Do the same with the remaining flour. The batter will be stiff and you might have to finish this by hand. Fold in the candies. Divide the mixture evenly between the 2 prepared pans pressing it in well so there are no air pockets; smooth the top. Bake until puffed and browned and a toothpick inserted into the center comes out clean, about 60 to 70 minutes. While they are still a bit warm, run a knife between the cakes and the pans to loosen them. Do not turn them out until they have completely cooled. Slice and enjoy.