Preheat oven to 325 grease and flour a 9 x 5 loaf pan. using an electric mixer set on medium speed, beat graded almond paste and sugar and butter until well mixed. Add eggs one at a time beating well between each addition. Beat on high until light and fluffy. sift the flour with baking powder and add to batter alternatively with milk. Beat on low until just combined and smooth. Do not over - mix, or cake will be tough. Pour batter into pan. Bake for 75 minuets or until an inserted toothpick pulls out clean. Cool cake, in pan on wire rack for 5 minuets. Un-mold carefully and finish cooling on rack before cutting.