How to Make It
Make the candied lemons: Cut 1 lemon in half lengthwise; thinly slice each half into 1/8-inch-thick half-moons. Using a Y-shaped peeler, remove the zest from the second lemon in 1/2-inch strips, and cut into thin strips; set aside. Juice the peeled lemon into a bowl, and set aside 3 tablespoons fresh juice.
Place lemon slices in a small saucepan, and add water to a depth of 1 inch. Bring to a simmer over medium. Drain and rinse under cold running water. Drain and return lemon slices to saucepan. Repeat process until lemon peels are soft and translucent, about 3 times, using fresh water each time. Return peels to saucepan; add sugar, 1 1/2 cups water, and uda pods. Bring to a simmer over medium, stirring occasionally. Reduce heat to medium-low, and simmer until the syrup is reduced to about 3/4 cup, about 25 minutes. Stir in lemon peel strips and 3 tablespoons lemon juice, and cook 1 minute. Remove from heat, and let cool while cake bakes. Remove and discard uda pods. Remove candied lemon slices from syrup, allowing excess syrup to drip off; reserve for serving. Reserve lemon syrup for brushing cake.
Make the almond teacake: Preheat oven to 350°F. Line the bottom of a 9-inch cake pan with a piece of parchment paper, and brush the sides and edges with 1 tablespoon melted butter. Spread 1/2 cup sliced almonds in an even layer on a small rimmed baking sheet, and bake in preheated oven until golden brown, 6 to 8 minutes. Set aside to cool. Pulse remaining 1 1/4 cups sliced almonds in a food processor until a coarse meal forms, about 10 times. Stir together almond meal, flour, baking powder, baking soda, and salt in a medium bowl.
Stir together egg yolks and 1 cup sugar in a large bowl until thoroughly blended and pale yellow. Fold in yogurt and almond extract, if using. Stir in flour mixture until just combined. (If the batter looks stiff you are on the right track! Avoid overmixing.)
Beat egg whites and remaining 1 tablespoon sugar with an electric mixer on medium-high speed until soft peaks form, about 90 seconds. Gently fold whipped egg whites into batter, and stir in remaining 1/2 cup melted butter.
Pour batter into the prepared pan and bake at 350°F until top is golden brown and a wooden pick inserted in the center comes out clean, about 40 minutes.
Remove the cake from the oven, and let cool in the pan 10 to 15 minutes. Invert the cake out onto a wire rack set inside a rimmed baking sheet. While the cake is still warm, brush surface and edges of cake with the syrup from the candied lemons, allowing the liquid to soak in before brushing with more. Do this until all the syrup is used up and has been absorbed by the cake. Top the cake with the toasted almonds, and transfer to a serving platter. Slice into wedges, and serve with the candied lemon slices and whipped topping.