Oatmeal Blueberry Muffins

1-1/2 cups all-purpose flour
3/4 cup rolled oats
2 teaspoons baking powder
1/2 teaspoon baking soda
1/4 teaspoon salt
1 beaten egg
3/4 cup milk
1/2 cup packed brown sugar
1/4 cup cooking oil
1/2 teaspoon vanilla
3/4 cup fresh or frozen blueberries

1. Grease twelve 2-1/2-inch muffin cups or thirty-six 1-3/4-inch muffins cups, or line them with paper bake cups; set aside. (If you don't have enough muffin pans, bake half the batter at a time. Refrigerate remaining batter.)

2. Stir together flour, rolled oats, baking powder, baking soda, and salt in a bowl. Make a well in the center of the mixture.

3. Combine egg, milk, brown sugar, oil, and vanilla in another bowl. Add egg mixture all at once to flour mixture. Stir just until moistened (batter should be lumpy.) Fold blueberries into the batter. Spoon the batter into the prepared muffin cups, filling each three-quarters full.

4. Bake in a 400 degree F oven for 16 to 18 minutes for 2-1/2-inch muffins or 10 to 12minutes for 1-3/4-inch muffins or until done. Cool in muffin cups on a wire rack for 5minutes; remove muffins from cups
Serve warm.
Makes 12 regular-size or 36 small muffins.

Muffin Tips:
"Ledges on the edges" are those unwanted rims around the edges of your muffins. To get nicely domed muffins without ledges, grease the muffin cups on the bottoms and only halfway up the sides.
After adding the liquid mixture to the flour mixture, stir just until moistened. If you try to stir out all the lumps, your muffins will have peaks, tunnels, and a tough texture.
Once the batter is mixed, put the muffins in the preheated oven right away. Batters that use baking powder and baking soda need to be baked immediately so the leavening power is not lost.
Muffins are done when their tops are golden.
To avoid soggy muffins, cool them in the baking pan only as long as directed in the recipe.