Pulse almonds in food processor 2 or 3 times or until chopped. Add brown sugar and 1 tablespoon flour; process 5 seconds. Add butter; pulse 5 times or until mixture is crumbly. Stir in oats; set aside.
Combine 2 cups flour and next 5 ingredients in a large bowl; add blueberries, tossing gently. Make a well in center of mixture.
Combine buttermilk, oil, and egg; add to flour mixture, stirring just until moistened. Spoon batter into greased muffin pans, filling two-thirds full, and sprinkle with oat mixture.
Bake at 400° for 15 to 20 minutes or until golden. Remove from pans immediately; cool on wire racks.