Streusel Sour Cream Muffin Coffeecakes

• 1
  

  cup sugar
  

• 2 ¹⁄₂
  

  cups flour
  

• ¹⁄₂
  

  teaspoon salt
  

• 1
  

  cup packed brown sugar
  

• 1
  

  cup cold butter, cut into small cubes
  

• 1
  

  teaspoon cinnamon
  

• 2
  

  cups toasted walnuts or 2 cups pecans, chopped
  

• 1
  

  cup sour cream
  

• 1
  

  large egg
  

• 1
  

  egg yolk
  

• 2
  

  teaspoons vanilla
  

• 1
  

  teaspoon baking soda
  

directions

• Set oven to 350 degrees.
• Set oven rack to middle position.
• Generously butter the bottoms, sides and tops of 18 non-stick muffin tins.
• In a large bowl stir together sugar, flour, salt and 3/4 cup brown sugar.
• Add in 3/4 cups cold butter and blend with a pasty blender or you fingers until the mixture resembles coarse meal with some pea-size butter pieces in the mixture; transfer 3/4 cup of the mixture to a bowl and blend in cinnamon, the remaining 1/4 cup butter and remainder 1/4 cup brown sugar with your fingertips or pastry blender until crumbly.
• Stir in the chopped nuts; chill for 15 minutes.
• Whisk together sour cream, egg, egg yolk, vanilla, baking soda.
• Add in the flour mixture until JUST combined (the batter will be stiff).
• Divide the batter evenly between the 18 muffin tins (they should be about two-thirds full).
• Sprinkle each with streusel topping (pressing it lightly into the batter).
• Bake coffeecakes for about 20-25 minutes, or until they test done with a toothpick inserted in the middle.
• Cool in the pans on racks for 30 minutes.
• Loosen the cakes with a small sharp knife, then carefully remove cakes from the muffin tins.