Pre heat oven to 160°C/320°F or 140°FF
Line a small loaf pan with baking paper. I use a 20cm x 9cm pan
In the bowl of a stand mixer, beat the butter and sugar on medium-high for a few minutes, until light and creamy. Scrape the sides of the bowl as needed.
Add the eggs and zest, then beat again on low-medium until well combined (don't worry if it looks a little separated)
Fold through the flour, almond meal, sour cream and lime juice, until just combined
Scoop mixture into prepared tin and smooth the top down with a spatula (it's a thick batter, so you'll need to really spread it)
Bake for 1 hour, or until a cake skewer comes out clean.
Cool in pan for 10 minutes, before transferring to a cake rack to cool completely