Entenmann's recipes are not in the public domain. However, the recipes are popular enough to have imitation recipes available. Entenmann's has existed in the United States for over 100 years.
To make an Entenmann's pound cake, use a mixer on high speed to cream 1/2 pound of butter with 2 cups of powdered sugar for five minutes. Starting with 1 2/3 cups flour and three raw eggs, add one egg and 2 tablespoons of flour, and beat for two minutes. Add the second egg and half the remaining flour, and beat for two more minutes. Add the third egg, the rest of the flour, and 1 tablespoon of lemon or vanilla extract. Beat for two minutes. Spread the creamy batter evenly into a greased 8 1/2-inch Pyrex loaf dish. Bake at 365 degrees Fahrenheit for 65 minutes or until a toothpick inserted into the center pulls out clean. Cool on a wire rack for 30 minutes.
For a New Jersey crumb cake, cream 1/2 cup of butter with 1 cup of sugar. Beat two large eggs with 3/4 cup of milk, then mix with the butter and sugar. In another bowl, mix 2 cups of flour and 2 teaspoons of baking powder, then stir into the butter mixture. Stir in 1 teaspoon of vanilla extract. Pour the batter into a greased 9 x 13 pan. For the crumb topping, mix 1 cup pf sugar, 2 cups of biscuit mix, and 2 teaspoons of cinnamon. Cut 1/2 cup of butter or margarine into the dry mix, and sprinkle over the batter in the pan. Bake at 350 degrees Fahrenheit for 30 minutes or until a toothpick stuck into the middle of the cake pulls out clean. When cool, top with 1/4 to 1/2 cup of powdered sugar.