Key Lime Cake — A Bright Finish to the First Jar of the Season

Finn turned eight this week. Sarah told me on Sunday that the birthday cake was chocolate with vanilla frosting, that he had eaten two pieces at breakfast before his party, and that he had mentioned the scrambled egg lesson four times during the party in reference to the summer visit. I sent him a card with a note inside that said: Dear Finn — I have been thinking about the scrambled egg lesson. I think you are ready for the real method. See you in August. Love, Grampa. Sarah read it to him over the phone and I heard him in the background say "the real method" with emphasis, as if this were a designation of great significance, which to a child who has decided cooking is important, it probably is.

The rhubarb is up at full height this week — the big ribbed stalks at their peak before the heat of June turns them woody, the leaves enormous and extravagant in the way rhubarb leaves are, the whole plant occupying its corner of the garden with authority. This is the seventh year I have harvested this patch, the seventh strawberry-rhubarb jam season, and the anticipation is the same as it was in year one. I cut the first rhubarb of the season Thursday — half a dozen stalks — and made a quick jam to mark the beginning: rhubarb only, sweetened just enough, a little orange zest, cooked fast and poured hot into a single jar. The first jar of the season is always a taste test rather than a finished product, a conversation with the fruit before the serious work begins.

The strawberry plants are in heavy blossom. If the weather holds through the next two weeks, the first berries should be ready by the last week of May. The combination of early rhubarb and late strawberries is what makes the jam possible — the rhubarb is always waiting for the strawberries, the longer-keeping acid fruit giving way to the sweet fragile one, and together they become something neither is alone. I have written about this combination many times and it still seems true each year in a way that requires saying again.

The first jar of the season sits on the counter cooling, and there is always a strange gap between pouring the jam and being able to eat it — the waiting that is part of the work. This year I filled that gap the same way I fill most gaps in the kitchen: I baked something. The lime has always felt right alongside rhubarb season to me, the same bright acid quality, the same way it cuts through sweetness and makes everything around it taste more like itself. Key Lime Cake has been my end-of-first-harvest ritual for three years now, and I think of it as the dessert that belongs to the moment between the first jar sealed and the first jar opened.

Key Lime Cake

Prep Time: 20 min | Cook Time: 35 min | Total Time: 55 min | Servings: 12

Ingredients

• 2 1/2 cups all-purpose flour
• 2 teaspoons baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon salt
• 1 cup unsalted butter, softened
• 1 3/4 cups granulated sugar
• 3 large eggs
• 1 tablespoon fresh lime zest (from about 3 limes)
• 1/3 cup fresh key lime juice (or regular lime juice)
• 1 cup buttermilk
• 1 teaspoon vanilla extract
• For the glaze: 1 cup powdered sugar, sifted
• 2–3 tablespoons fresh key lime juice
• 1 teaspoon lime zest

Instructions

1. Preheat oven. Heat oven to 350°F. Grease and flour a 9x13-inch baking pan, or two 9-inch round cake pans.
2. Mix dry ingredients. Whisk together flour, baking powder, baking soda, and salt in a medium bowl. Set aside.
3. Cream butter and sugar. Beat softened butter and granulated sugar together on medium-high speed for 3–4 minutes until light and fluffy.
4. Add eggs and zest. Beat in eggs one at a time, then mix in the lime zest and vanilla extract.
5. Alternate wet and dry. On low speed, add the flour mixture in three additions, alternating with the buttermilk and lime juice in two additions. Begin and end with the flour mixture. Mix just until combined — do not overmix.
6. Bake. Pour batter into prepared pan(s) and bake 30–35 minutes, until a toothpick inserted in the center comes out clean and the top is lightly golden.
7. Cool. Let the cake cool in the pan for 10 minutes, then turn out onto a wire rack and cool completely before glazing.
8. Make the glaze. Whisk together the powdered sugar, lime juice, and lime zest until smooth and pourable. Add juice a little at a time to reach a thick but drizzleable consistency.
9. Glaze and serve. Drizzle glaze evenly over the cooled cake. Allow to set for 10 minutes before slicing.

Nutrition (per serving)

Calories: 385 | Protein: 4g | Fat: 16g | Carbs: 57g | Fiber: 1g | Sodium: 210mg