In a bowl, whisk together all purpose and whole wheat flour, baking powder, baking soda and salt. Stir in dates and cocoa nibs to coat; set aside.
In a large bowl, using an electric hand mixer, beat together butter and sugar until fluffy. Beat in eggs one at a time, beating well after each addition.
In a small bowl, stir together vanilla and instant coffee until dissolved. Add to butter mixture and beat into mixture. Stir in buttermilk and add flour mixture; stirring until evenly combined.
Line or lightly grease muffin tin and scoop batter among 9 muffin cups. Top each muffin with the quartered dates and bake in center of 375 F (190 C) oven for about 18 minutes or until golden and cake tester inserted in center comes out clean.
Tips: Let muffins cool completely then wrap individually and freeze for up to 2 weeks. Store in refrigerator for up to 5 days and warm through in the microwave before serving.
You can find cocoa nibs in the natural or organic section of the grocery or health food store.