Surely you're not buying cake mixes to make coffee cake. I made this the other day, and it's really good. Easy, too.

If you don't want to buy liquid buttermilk, it's easy to keep the dried product on hand for recipes like this. Just follow the directions on the package.

If you don't have either kind of buttermilk, you can make a substitute by putting 1 tablespoon freshly squeezed lemon juice or white vinegar in a cup and fill it with 2% or richer milk. Let stand for about 15 minutes and it will start to look curdled.

The recipe called for a 9 by 13 inch pan, but that seemed too large, and the cake was spread kind of thin. But you all are at lower altitudes so might get more rising action. I've compromised and suggested a 8 by 12 pan because I'm not sure if a square pan would be big enough.

Buttermilk Coffee Cake
2 1/4 cups regular all-purpose flour (sift before measuring)
1/2 teaspoon salt
1/2 teaspoon cinnamon
1 cup brown sugar, firmly packed
3/4 cup granulated sugar
3/4 cup salad oil
1/2 cup walnuts, coarsely chopped
1 teaspoon cinnamon
1 teaspoon soda
1 teaspoon baking powder
1 egg, slightly beaten
1 cup buttermilk

Sift the flour again with salt and 1/2 teaspoon cinnamon into the large bowl of an electric mixer. Add brown sugar, granulated sugar, and salad oil. Mix on medium speed until well-blended and feathery. Take out 3/4 cup of the mixture for the topping into a medium size bowl, mix in the nuts and 1 teaspoon cinnamon. Set aside.

To the remaining mixture, add soda, baking powder, egg, and buttermilk. Mix until smooth and spoon into a buttered 8 by 10 pan and level off the top. Sprinkle the reserved topping evenly over the top and lightly press in with the back of a spoon. Bake in a 350 degree oven (325 degree for glass pan) for 25 to 30 minutes until it tests done. Cut in squares and serve warm or cold. I thought it was better the next day.

You could grease the pan with baking spray or whatever, but I felt like the cake picked up the butter flavor from the pan, and had a richer taste.