Recipe: Basic Donuts (Donut Wizard)

I have the Donut Wizard Recipe Booklet. I just tried to make the basic donuts. I tried twice, my batter turns into cement. Here is the recipe:

BASIC DONUTS

2 cups flour
1/2 cup sugar
1 tsp baking powder
1 egg (beaten)
1/2 cup milk
1 tsp vanilla extract
4 tsp oil

Preheat oven to 325 degrees F. Lightly spray donut pan with non stick spray oil.

Mix together flour, sugar and baking powder. Next, add egg, milk, oil and vanilla and mix vigorously until well blended. Pour batter into molds up to 2/3 full.

Bake 8 minutes or until tops spring back when lightly touched. Let cool.

Remove and dip into glaze or cinnamon and sugar if desired. Decorate with your favorite toppings.

Makes approximately 12 large donuts or 36 bite size donuts.

They have about 10 recipes. Let me know if you want the rest of them. Let me know if this recipe works for you, I don't know what I'm doing wrong.

Note from Tracy Scott - England:
I also tried to make this, and produced cement, I thought it was my English measures!! I managed to solve it by adding another 1/2 cup of milk, and that seemed better. Not like the pouring that is featured on the box though!!