Streusel: Mix ingredients with electric mixer fitted with paddle attachment on low speed to desired crumb size. Set aside.
Muffins: Whisk dry ingredients in large bowl. Whisk liquid ingredients in a separate bowl until blended. Make a well in center of dry ingredients. Add liquid ingredients all at once; mix just until combined. (Batter will be lumpy.)
Use #20 scoop to portion batter into 12-cup muffin tin coated well with cooking spray. Top each with 3-1/2 Tbsp. Streusel.
Bake in 400°F standard oven 15 to 18 min. or until wooden pick inserted in center comes out clean. Let cool in pan on wire rack 15 min. Remove from pan. Serve warm or at room temperature.