Preheat oven to 350 degrees. Grease and flour a 9 inch springform pan with nonstick spray and set aside. Mix together streusel ingredients until crumbly, or pulse ingredients using a food processor (this is my preferred method). Set aside.
Cream together butter, sugar, and eggs with an electric mixer until creamy. Add in vanilla and greek yogurt and mix until smooth.
In a medium sized bowl, sift together the flour, salt, baking powder, and baking soda. Gradually add dry ingredients to the wet ingredients beating over low speed.
Pour half of the batter into prepared pan. Sprinkle with half of the streusel mixture then top with remaining batter. Sprinkle the rest of the streusel mixture over the top.
Bake in preheated oven for 50-60 minutes until cake is cooked through and a toothpick inserted near the center comes out clean. Cool completely on a wire rack.
To make the glaze: combine melted butter, powdered sugar, 1 Tablespoon milk, and vanilla in a small bowl. Whisk until smooth, only adding additional milk if mixture is too thick. Drizzle over the top of cooled coffee cake. Slice and enjoy!