My friend Cynthia no longer has a positive relationship with dairy products. They are not friends.

So she offered me a challenge: Find a recipe for a lemon cake that did not use milk. Yogurt was OK. Many people who are lactose intolerant can eat yogurt, as the live bacterial cultures help dispense with the lactose.

I found several recipes for lemon-yogurt cakes, then narrowed it down to a few that did not use butter, either. A couple substituted olive oil, and that lemon-olive oil flavor combination intrigued us both.

I baked three cakes. The first had a very good lemon flavor — tart and assertive from both lemon juice and zest. But it was very dense. Like a brick, actually.

Then came two attempts to lighten it up, and a bunch of us undertook the brave job of tasting. This recipe was the favorite but also the fussiest — sorry. It calls for beating egg whites to light, foamy peaks and folding them into the batter, providing lift for all that yogurt and oil.

But it’s worth it for those who love lemon. If you have a lemon tree that’s in summer overdrive, this is a great way to use your bounty, even if your relationship wtih dairy products is just fine.

LEMON-YOGURT CAKE WITH OLIVE OIL

1-1/2 cups flour
2 teaspoons baking soda
1/2 teaspoon salt
3 extra-large eggs, separated
3/4 cups sugar, divided
1 cup plain nonfat Greek yogurt
1/3 cup fresh lemon juice (about 1 large lemon)
Zest of 1 lemon (about 2 teaspoons)
1 teaspoon vanilla extract
1/2 cup olive oil

Heat oven to 350 degrees. Grease a 9-inch square cake pan.

Sift together flour, baking soda and salt.

Beat egg whites on medium-high speed of mixer until light and fluffy. Slowly add 1/4 cup of the sugar and beat until soft peaks form. (Be sure beaters and bowl are cool and dry, and that there are no bits of yolk in the whites.)

In separate bowl, whisk together remaining 1/2 cup sugar and egg yolks until well combined and a light lemony color. Whisk in yogurt, stirring well, then lemon juice and zest, then vanilla. Slowly whisk in dry ingredients (batter will become foamy as baking soda combines with acid in the lemon juice; do not be alarmed). Slowly add olive oil and stir until incorporated. Fold in beaten egg whites, stirring until no white streaks remain. Pour into prepared pan and bake 30-35 minutes, until a pick inserted in center of cake comes out clean.

Nutritional information unavailable.

VARIATIONS

To simplify: If you really don’t want to beat egg whites, skip that step and combine 3 whole eggs with sugar. Proceed with the remaining steps.

Adjust the flavor: For more tartness, add another teaspoon lemon zest. For less, increase sugar to 1 cup and eliminate zest.

———

Send recipe requests to "By Request," Honolulu Star-Advertiser, 7 Waterfront Plaza, Suite 210, Honolulu 96813; or email bshimabukuro@staradvertiser.com.