To prepare the cake batter:

1. Preheat the oven to 350°.

2. Toast the pine nuts over very low heat in a dry sauté pan until they have just begun to take on a golden color, about 8 minutes. Remove from the stove and reserve.

3. Meanwhile, cream the sugar, butter, and lemon zest together in a KitchenAid with the paddle attachment, beginning on low and then increasing the speed to medium as the mixture combines. Be sure to scrape down the sides as you go to make sure everything mixes evenly.

4. When the mixture is quite smooth, add the flour and baking powder. Mix until the dry ingredients are just incorporated, and then begin adding the eggs, one by one, waiting until each egg is thoroughly mixed in before adding the next. Turn the KitchenAid up to high for about 5 seconds to combine everything thoroughly, then scrape down the sides and the bottom with a spatula and mix in any bits that have failed to incorporate.

5. Add the yogurt, and mix in with the paddle attachment until it’s thoroughly incorporated.

6. As you continue mixing, add the lemon juice and incorporate. The batter should be stiff and airy, a homogenous mix. Scrape down the sides and bottom and mix well with a spatula to make sure that there are no lumps of butter and that the flour is all incorporated. Then transfer the mixture to a large bowl.

To prepare the meringue:

1. Beat the egg whites in the mixer with the whisk attachment at medium speed until they’ve formed a froth.

2. While the egg whites are still whisking, add the sugar In a slow stream. Mix at medium for 20 seconds to combine.

3. Turn the mixer up to high and continue beating until the meringue forms stiff peaks, about 4 minutes; when you lift the whisk, the meringue should form a bird’s-beak shape off the end.

To finish the cake:

1. Fold a third of the meringue into the batter, using a rubber spatula to combine well.

2. Add the rest of the meringue and fold in well until the mixture is combined.

3. Fold in the pine nuts.

4. Spray 3 2-pound loaf pans evenly and on all sides with a nonstick coating.

5. Fill each loaf pan two-thirds full with the batter. Smooth and flatten the tops with the spatula or the back of a wooden spoon, then bake the loaves on the middle rack until you can put a knife into each loaf and bring it out clean, about 45 minutes.

6. Remove the cakes from the oven, turn them out on a cake rack, and let them rest for 30 minutes before serving.