Preheat the oven to 300 degrees F (150 degrees C). Grease and flour an 8x8-inch baking dish.

Beat sugar and butter together until light and fluffy, about 3 minutes; beat in eggs and lime juice. Stir flour and baking powder into butter mixture until combined. Pour batter into the prepared baking dish.

Bake in the preheated oven until brown and a toothpick inserted in the center comes out clean, about 25 minutes. Garnish with chopped peanuts.