In a large mixing bowl, combine cake wheat flour and baking powder. Use a pastry cutter to cut in cold butter until the mixture resembles coarse crumbs. Slowly add in ice water and lemon juice, mixing just until a smooth dough forms. Wrap the dough in plastic wrap and refrigerate for a minimum of 3 hours.

Prepare the aromatic syrup by combining water, granulated sugar, ground cardamom, and rose essence in a medium saucepan over medium heat. Bring to a gentle simmer and let cook for about 10 minutes until thickened. Cool while shaping puris.

Divide the chilled dough into eight equal portions. Roll into thin squares, brush with melted butter, and sprinkle with cornflour. Roll each square into a Swiss roll shape, then cut into 1.5 cm pieces.

Heat vegetable oil in a deep frying pan to around 350°F (175°C). Fry two puris at a time for about 3 minutes on each side until golden brown and puffed up. Drain on paper towels.

Serve Flaky Banana Puris drizzled with the cooled rose-cardamom syrup and topped with chopped pistachios or almonds. Enjoy warm.