Preheat oven to 180°C. Lightly grease 3 loaf tins and flour work surface. Sift together flour, salt and baking powder in a large bowl. Add sugar. Rub in butter, using your fingers, until mixture resembles fine breadcrumbs. Mix together buttermilk, vanilla essence and eggs. Pour into flour mixture and stir to combine. Knead to form a soft dough. Turn out onto surface and roll into a fat sausage shape. Divide dough into 18 pieces and roll into balls. Pack 6 balls into each loaf tin. Bake for 30 minutes, reduce heat to 120°C and bake for a further 30 minutes. Remove from oven, break 6 buns apart and break each one in half. Place on a baking tray and return to oven for 3–4 hours at 100°C to dry out. Store in an airtight container.