1/2 cup butter or margarine
1 1/2 cups brown sugar
1 1/2 cups white sugar
1/2 cup vegetable oil
1 egg
1 teaspoon vanilla extract
1/2 teaspoon lemon juice
2 cups all-purpose flour
1 teaspoon baking powder
1/4 teaspoon salt
1 teaspoon ground cinnamon
10 muffins, split
Preheat oven to 350 degrees F (175 degrees C). Grease and flour 2 muffin cups or small pans.
Sift together the brown sugar, white sugar and vegetable oil. Set aside.
In a large bowl, cream together the butter, brown sugar and white sugar until light and fluffy. Beat in the egg, one at a time, then stir in the flour, baking powder, salt, cinnamon and vanilla. Mix in the flour mixture by itself. Fold the lemon juice into the batter. Spread half of the batter into the center of the muffin tin. Place half of the muffins on the bottom of an ungreased 9x5 inch pan, or on greased baking sheets.
Bake at 350 degrees F (175 degrees C) for 20 to 34 minutes in the preheated oven. Allow muffins to cool completely before removing from pan.
Double the batter in the bottom of the pan. Sprinkle half of the lemon mixture over the top of the muffins, then top with half of the remaining batter. Cover the muffins with a covering of aluminum foil. Brush remaining lemon lemon mixture over the muffins.