In a large bowl, combine flour, cornstarch, powdered sugar, cocoa powder, baking powder, cinnamon, ginger, cayenne, and salt. Stir or whisk to evenly distribute ingredients and break up any lumps.
In a measuring cup or small bowl, combine coconut oil and 3 tbsp/45ml coconut milk.
Pour into flour mixture and stir, trying to get all powder incorporated until mixture just holds together. If too dry, add more coconut milk 1 tbsp/15ml at a time. Do not over moisten. Dough should just hold together when squeezed, but not be moist.
Gather dough into disc, cover in plastic wrap and chill for 10-15 minutes. Do not leave for longer as dough will become to hard to roll. If leaving dough longer, allow to come to just below room temperature before rolling.
Preheat oven to 350°F/175 C. Line baking sheets with parchment.
Between two sheets of parchment, roll out dough without adding any additional flour. Roll to 1/4”/6mm thick.
Use a 2”/5cm cookie/biscuit cutter to cut desired shapes or cut into squares with a knife.
Excess dough can be gathered up and rerolled for more cookies.
Place on prepared baking sheets with 1”/2.5cm between cookies (they do not spread much).
Bake for 8-10 minutes until just dry to touch. Use less time for softer cookies and longer for more crumbly, crisp ones.
Allow to cool on baking sheets for 5 minutes before transferring to a cooling rack.
Once cookies are completely cool they can be coated.
Chop chocolate finely and place in a heat proof bowl over a pot of simmering water until mostly melted. Alternatively, melt in the microwave in blasts of 15 seconds or less, stirring after each one. Allow residual heat to finish melting chocolate.
Add the coconut oil and stir until smooth.
Dip cookies in chocolate mixture at an angle and shake to remove excess before placing on cooling rack or lined baking sheets. Cookies can also be completely coated using a fork to lift them. Or drizzle chocolate on cookies in a zigzag pattern.
While chocolate is still wet, sprinkle on crushed red pepper flakes or flaky sea salt if desired.
Allow to harden completely before moving to an airtight container. Can be stored for up to 5 days.