Makes 8 cupcakes
1/2 cup blanched whole almonds
4 tablespoons unsalted butter, melted, plus 9 tablespoons unsalted butter, softened
1/2 cup packed brown sugar
2 tablespoons light corn syrup
1/2 pineapple, peeled, cut in half lengthwise, cored, and cut into 1/4- to 1/2-inch dice
1 1/2 cups pastry flour
3/4 cup sugar
3/4 teaspoon baking powder
3/4 teaspoon baking soda
1/2 teaspoon salt
1/2 cup sour cream
3 large egg yolks
1 teaspoon vanilla extract
Preheat the oven to 350 degrees F.
Spread the almonds on a baking sheet and toast, shaking the pan occasionally, until lightly golden, 15 to 20 minutes. Set aside to cool.
Stir together the 4 tablespoons of melted butter, brown sugar, and corn syrup and evenly coat the bottoms and sides of a cupcake pan. When the almonds are cool, arrange a few around the bottom rims of a lightly greased cupcake pan, with one in the center, gently pressing them into the brown sugar mixture. Arrange the diced pineapple in an even layer on top of the brown sugar mixture.
In a mixing bowl, combine the pastry flour, sugar, baking powder, baking soda, and salt and thoroughly mix.
In another bowl, whisk together the 9 tablespoons of softened butter, sour cream, egg yolks, and vanilla. Add to the dry ingredients and mix with an electric mixer at medium speed about 1 1/2 minutes, scraping down the sides of the bowl occasionally, until thick and smooth.
Using a small spatula, spread the batter evenly over the fruit, building up the outside edges so the cupcakes will be level when baked.. Bake 15 to 20 minutes, until golden brown and a tester inserted in the center comes out clean. Transfer to a rack to cool 3 to 5 minutes (no longer) and then invert onto a serving plate, repositioning the fruit as necessary.