Banana Nut Muffins with Oatmeal Streusel

The wholemeal flour and oatmeal in these banana-nut muffins contain whole grains. A reasonable amount of walnuts contains fiber, vitamin E, and unsaturated fats. English walnuts (the most common variety in supermarkets) provide almost 20 percent of the daily value of heart-healthy omega-3 fats per serving.
Preheat the oven to 375 degrees.To make the muffins, lightly pour 1 1/2 cups all-purpose flour and wholemeal flour into dry measuring cups; flatten with a knife. Combine the flour and the next 4 ingredients (with the added salt) in a large bowl; make a well in the center of the mixture. Combine the banana and the next 4 ingredients (with egg) in a bowl; mix well. Add to flour mixture. Stir until they are moist; add the walnuts. Place 12 muffin tins in the muffin tins. Spoon the batter into 12 muffin tins.To make the streusel, combine the oatmeal and other ingredients in a small bowl. Beat with a baking blender or two knives until the mixture resembles coarse flour. Sprinkle the dough with streusel. Bake at 375 ° C for 22 minutes or until a wooden stick inserted in the middle comes out clean.