Preheat the oven to 425 degrees F. Grease a 12 cup muffin tin with 2 tablespoons of the oil. In a large mixing bowl, combine the remaining 1/2 cup of the oil and sugar. Mix well. Add the eggs, 1 at a time, beating well after each. Sift the dry ingredients together. Alternately add the sifted ingredients and the milk to the egg mixture. Add the vanilla. Fold in the rice. Fill the tins with the batter, about 3/4 full. Bake for 25 minutes or until golden brown and the center of each muffin springs back. Remove from the oven and cool for 2 minutes. Remove the muffins from the tin and cool on a wire rack. Serve the muffins warm with butter and jam.