In large mixing bowl or bowl of stand mixer, mix butter, coconut sugar and lemon zest on high speed until smooth and creamy.

In separate bowl, whisk together flour, almond flour, rosemary and sea salt. Add to butter mixture and mix on low speed until mixture resembles coarse bread crumbs.

Add cranberries and walnuts and knead by hand until soft dough forms.

Shape dough into 8-inch log. Wrap in plastic wrap and refrigerate 1 hour, or until firm.

Preheat oven to 350 degrees F. Line large baking tray with parchment.

Unwrap log. With sharp knife, cut into 1/4-inch-thick slices. Arrange on prepared tray.

Bake 13-15 minutes, or until bottoms are lightly golden brown. Cool on wire rack.

Store cranberry shortbread in airtight container at room temperature up to 5 days.