Cupcakes: Preheat oven to 350°F. Line 12-cup muffin pan with paper liners. In large bowl, whisk together flour, cocoa powder, baking powder, baking soda and salt; set aside. In food processor or blender, purée beets, coconut milk and vanilla until smooth; set aside.
Using electric mixer, beat coconut oil with sugar until light and fluffy. Beat in eggs, one at a time, incorporating each one before next addition. With mixer on low, alternately add flour mixture in 3 parts and beet mixture in 2 parts, starting and ending with flour mixture, scraping down bowl as needed. Fold in crushed cookies.
Divide half of the batter among muffin cups. Add 1 tsp guava paste to each muffin cup; top with remaining batter. Bake for 15 to 20 minutes or until tester comes out clean when inserted into center of cupcakes. Let cool completely in pan on rack.
Frosting: Using electric mixer, beat coconut oil until light and fluffy. With mixer on low speed, beat in icing sugar, coconut milk and vanilla until smooth. Increase speed to high; beat for 1 to 2 minutes or until light and fluffy.
Spoon frosting into piping bag fitted with round tip; pipe over cupcakes to resemble ghosts. Alternatively, spoon frosting into resealable plastic bag and snip off one corner; pipe over cupcakes. Decorate each cupcake with 2 candy eyes.
Substitute mini dark chocolate chips for candy eyes if desired.