In a medium bowl, add the matcha and drizzle the boiling water over top. Stir together to bloom the matcha. Stir in the tahini, maple syrup, and vanilla until combined.
In a high-speed blender, add the pumpkin seeds and coconut and blend on high into a fine meal/flour, scraping down the sides if needed. Pour into the bowl along with the salt. Use a rubber spatula to stir until just combined (don’t overmix or it can turn a bit oily). Transfer to a parchment lined loaf pan and press into an even layer.
If making the chocolate topping, add chocolate chips to a microwave safe bowl and microwave in 20 second intervals until just melted, stirring after each time. Stir in the tahini until combined.
Pour the chocolate on top of the matcha mixture and spread it around as best you can. Top with a sprinkling of sesame seeds and flaky salt, if using.
Place in the freezer to chill for at least 2 hours. Slice into squares or bars of whatever size you’d like (I got 15 squares out of mine). Store in an airtight container in the freezer.