Rose Prince's Baking Club: goats' cheese muffins Baking powder is formulated to work well with cakes but when making breads and muffins, bakers will often use a combination of baking powder and bicarbonate of soda, and give the dough that extra lift. The addition of either buttermilk, semi-skimmed milk soured with a little lemon juice or low-fat yogurt helps boost the production of carbon dioxide, making a yet lighter loaf or muffin. You need to work quite quickly when making the savoury muffins below, because on contact with the acids in the buttermilk or sour milk/yogurt, bubbles will soon form in the dough. Makes 12 Equipment A bun tray and 12 15cm sq sheets of baking parchment, pressed onto the end of a rolling pin to make a pleated paper case 300g/10½oz plain flour 2 tsp baking powder 1 tsp bicarbonate of soda ¾ tsp fine salt A large handful of rocket leaves, roughly chopped, or parsley About ½ tbsp chopped rosemary leaves 100ml/3½fl oz extra virgin olive oil 230ml/8fl oz plus 1 tsp buttermilk, low-fat yogurt or soured milk 200g/7oz fresh, firm-textured goats" cheese, cut into cubes (rind left on) A little sea salt, to sprinkle Preheat the oven to 200C/400F/gas 6. Sift the flour into a bowl with the baking powder, bicarbonate of soda and fine salt. Stir in the rocket and rosemary leaves with the extra virgin olive oil, then add the buttermilk with the goats" cheese cubes. Stir to make a well-mixed dough. It will be quite stiff and you will quickly see bubbles forming in it. Place a heaped dessert spoonful into each paper case and then put the muffins in the oven straight away. Bake until well risen and golden. It is lovely to eat these warm, opened out and spread with a little butter. They also reheat well and keep fresh for about a day. Your letters "Which is the best apple to use in an apple pie?" asks Leonie Anderson, who has a glut of windfalls. "Some of the trees in the garden are so old I do not know what they are or if they are better for cooking as well as eating raw," she writes. I think that every apple cooks well, and do not necessarily subscribe to the idea that a Bramley is the only "cooker." Bramleys actually make wonderful raw apple juice, and most apples are brilliantly tangy in pies and tarts. The French love to cook with what they call pommes vertes (green apples) and we call Granny Smiths; but I like to use the new season's apples in cooking because they are still acidic and have not yet developed that characteristic, mellow, classic English apple taste - think Cox's and Russets. Incidentally I was once taught by a champion American apple pie cook in Oregon to add a little cheddar to the pastry with great savoury-sweet effect. Garden Apple ID will help you discover what type of apples you have in your garden. Next week Kringle - a sweet Danish stuffed bread. You'll need milk, butter, plain flour, caster sugar, cardamon, yeast, eggs, vanilla, raisins/sultanas/dried cranberries/nuts, nibbled sugar (Bakery Bits)