Cardamom and lime syrup cake

Cake

• 200 g unsalted butter, softened, plus extra for greasing
• 1 tbsp green cardamom pods (see Tips)
• 240 g white sugar
• 200 g roasted unsalted cashew nuts
• 4 eggs
• 170 g natural yoghurt
• 240 g self-raising flour

Syrup

• 120 g white sugar
• 1 lime, zest only, no white pith
• 1 tbsp lime juice
• 90 g water