Use a food processor to crush Oreos into fine crumbs. Mix crumbs with 1/4 c. softened butter; press mixture into 8x8 inch square pan.

Refrigerate until firm.

In a large mixing bowl, combine remaining butter, powdered sugar, fresh raspberries, preserves, and lemon zest.

Using a hand mixer, beat at high speed 2-3 minutes.

Spread over chilled crust.

Return to refrigerator to set; cut into bars and serve.

*Keep refrigerated until ready to serve.