All ingredients are available at Tesco, Sainsbury’s, Waitrose, ASDA, and Morrisons. All-purpose flour, sugar, and baking ingredients (baking powder, baking soda, salt) are in the baking aisle. Olive oil is in the pantry section, and fresh citrus (lemons and oranges) is available in the produce section. Powdered sugar is also in the baking aisle.