Maple Walnut Coffee Cake

INGREDIENTS

Streusel::

1/2 cup

light brown sugar

1/4 cup

all-purpose flour

1/4 cup

finely chopped California walnuts

1/2 tsp

ground cinnamon

3 tbsp

unsalted butter, melted

Coffee Cake::

2 cups

all-purpose flour

1 tsp

baking powder

1/2 tsp

baking soda

1/2 tsp

fine salt

1/2 cup

light brown sugar

1/2 cup

chopped California walnuts

1/2 cup

maple syrup

1/2 cup

vegetable oil

1/4 cup

whole milk

large eggs, beaten

1 tsp

maple extract (optional)

8 oz

sour cream, at room temperature

Topping::

1/2 cup

powdered sugar, sifted

2 tbsp

maple syrup