Using a medium bowl, add walnuts, brown sugar, granulated sugar, cinnamon and nutmeg; stir until well combined.

Add the melted butter; stir until well combined.

Add the flour; stir until well combined. Set Streusel aside.

Preheat oven to 350°F.

Grease and flour (or spray with nonstick spray) a 9”x3” round cake pan. Set pan aside.

In medium bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon and nutmeg until well combined; set mixture aside.

Using a countertop mixer, cream together the sugars and butter until light and fluffy (~2-3 minutes on medium speed).

Add eggs, one at a time, mixing after each addition.

Add vanilla, lemon juice and sour cream; mix on low speed until well combined.

Add carrots, walnuts and raisins to the bowl; mix on low speed until well combined.

Add dry ingredients to the bowl; mix on low until just combined.

Pour ~½ of the batter into greased cake pan. Crumble half of the streusel on top of batter. Pour remaining batter on top and crumble remaining streusel on top of batter. (Tip: Leave some bigger chunks of Streusel on top!)

Bake at 350°F for 45 minutes. Open oven and tent the top of the cake with a piece of foil to prevent the streusel from burning. Continue baking for another 55-60 minutes, or until a toothpick inserted into cake comes out mostly clean.

Place cake on cooling rack for at least 30 minutes.

Using a medium bowl, whisk together the cream cheese and butter. Add brown sugar, vanilla, and cinnamon; mix until smooth. Add the powdered sugar and milk; mix until smooth.

Place glaze in a piping bag with a round tip (or a sandwich bag with one corner snipped off). Drizzle cooled cake with glaze before slicing.