Cook the Quinoa: In a medium saucepan, bring rinsed quinoa and water (or broth) to a boil. Reduce heat to low, cover, and simmer for 15 minutes until liquid is absorbed. Remove from heat and let steam, covered, for 5 minutes.
Season & Cool: Fluff quinoa with a fork. Stir in olive oil, honey, salt, cinnamon, and vanilla. Fold in pistachios, coconut, lemon zest, and cardamom. Spread on a plate and cool completely.
Prep Dates: Using a paring knife, slice each date lengthwise and remove pits. Gently open to create a pocket.
Fill Dates: Spoon or pipe cooled quinoa mixture into each date, filling just to the top. Mound slightly if desired.
Optional Toasting: For warm, crisp edges, bake at 350 °F (175 °C) for 5–7 minutes or broil 1–2 minutes until golden. Watch closely to prevent burning.
Serve: Arrange on a platter and garnish with extra chopped pistachios, a sprinkle of coconut, or a mint leaf.