Maple Walnut Cake

Directions

1. 1
   Preheat oven to 350 degrees F. Line a 9-inch square baking pan with parchment, lightly butter and dust with flour. Tap out excess.
2. 2
   In a medium bowl whisk together the flour, baking powder, baking soda and salt.
3. 3
   In a separate large mixing bowl on medium speed beat the butter, maple syrup and sugar together until pale and fluffy, 3 to 5 minutes, it might look a little curdled, that's ok.
4. 4
   Beat in the eggs, one at a time then the vanilla.
5. 5
   On low speed beat in the flour in three additions, alternating with the sour cream; beat just until combined. Spoon or pour the batter into the pan and spread out evenly.
6. 6
   Bake about 40 minutes or until a toothpick comes out clean from center. Cool in pan on wire rack. Once cooled carefully lift out using the parchment.
7. 7
   In a large bowl stir the maple syrup and butter together. On low speed beat in the confectioners' one cup at a time. Continue beating on medium speed 5 minutes until fluffy. If it seems too thin add a little more confectioners' sugar.
8. 8
   Refrigerate the frosting 10 - 15 minutes to make for easier frosting. Frost the top of the cake and sprinkle with the nuts pressing them down gently to help them stick.
9. 9
   Store well covered in a cool place up to 5 days.