In a large bowl, combine butter and shortening. Beat with an electric mixer on medium to high speed for 30 seconds. Add the 3/4 cup brown sugar, the baking powder, pumpkin pie spice, baking soda, and salt. Beat until combined, scraping side of bowl occasionally. Beat in egg and the 2 teaspoons vanilla until combined. Beat in as much of the 2 cups flour as you can with the mixer. If necessary, use a wooden spoon to stir in remainder of the 2 cups flour. Divide dough in half. Cover and chill about 4 hours or freeze about 1 hour or until easy to handle.

Meanwhile, in a medium bowl, combine cream cheese, the 1/4 cup brown sugar, the 1 teaspoon flour, and the 1/2 teaspoon vanilla. Beat on medium speed until smooth. Stir in the 3/4 cup sunflower kernels.

Preheat oven to 350 degrees F. Lightly grease a cookie sheet; set aside. On a lightly floured surface, roll dough, one portion at a time, into a 10-inch square. Using a pastry wheel, cut each dough square into sixteen 2-1/2-inch squares. Place dough squares 2 inches apart on prepared cookie sheet. Make 1-inch-long slits from each corner toward the center of each square.

Spoon about 1 teaspoon of the cream cheese mixture onto the center of each dough square. Bring alternating corners of dough up over filling to the center to form a windmill; lightly press to seal.

In a small bowl, combine granulated sugar and cinnamon; sprinkle lightly over cookies. Press additional sunflower kernels in centers of cookies. Bake in preheated oven for 8 to 10 minutes or until edges are lightly browned. Transfer cookies to a wire rack; let cool. Makes 32 cookies.

To Store: Place cookies in a single layer in an airtight container; cover. Store in the refrigerator for up to 3 days.