Pre-heat oven to 190°C (170°C fan-forced). Line a 10 x 20cm loaf pan with baking paper.
Combine Stevia, eggs, oil, lemon juice, sour cream and lemon rind in a large mixing bowl. Whisk until well combined.
Add flours and baking powder to wet ingredients. Mix well and pour into the prepared pan. Bake for 33-35 minutes until just golden and an inserted skewer comes out clean. Allow to cool.
For the glaze, mix together the ingredients and drizzle over the cake. Sprinkle with lemon rind.