Bluebery Tart with Walnut Crust

This blueberry tart is one of my favorite desserts for summer. It's easy, light and delicious.

Crust:
1/2 cup walnuts
1 cup graham cracker crumbs, preferably whole wheat
1 large egg white
1 tbsp butter, melted
1 tbsp peanut or canola oil
Pinch of salt

Filling:
8 oz. reduced-fat cream cheese, softened
1/4 cup reduced-fat sour cream
1/4 cup plus 2 tbsp pure maple syrup, preferably grade B, divided
2 cups fresh blueberries

1. To prepare the crust: Preheat oven to 325 F

2. Coarsely chop walnuts in a food processor. Add graham crackers and process until mixture looks like fine crumbs.

3. Whisk egg in a medium bowl until frothy. Add the crumb mixture, butter, oil and salt; toss to combine. Press the mixture into the bottom and 1/2 inch up the sides of a 9-inch removable-bottom tart pan. Set pan on a baking sheet, bake until dry and slightly darker around the edges (about 8 minutes). Cool on a wire rack.

4. To prepare filling: Beat cream cheese, sour cream and 1/4 cup maple syrup in a medium bowl with an electric mixer on low speed until smooth. When the crust is cool, spread the filling evenly into it, being careful not to break up the crust. Arrange blueberries on the filling, pressing lightly so they set in.  Drizzle the remaining 2 tbsp maple syrup over the berries. Chill for at least 1 hour to firm up.