Preheat oven to 375°F (190°C). Line a muffin tin with paper liners and lightly spray with oil.
In a small bowl, combine nut filling ingredients: toasted walnuts, pistachios, brown sugar, cinnamon, and melted butter. Set aside.
In a large bowl, whisk together dry ingredients: flour, baking powder, baking soda, salt, cinnamon, cardamom, and nutmeg.
In a separate bowl, whisk wet ingredients: Greek yogurt, honey, melted butter, eggs, vanilla, and lemon zest.
Pour wet ingredients into dry and gently mix until just combined. Do not overmix.
Spoon batter halfway into each muffin cup. Add a teaspoon of nut filling, then top with more batter to cover.
Bake for 18–20 minutes, until muffins are golden and a toothpick inserted comes out clean.
While muffins are still warm, brush tops with honey glaze. Let glaze soak in and muffins cool slightly before serving.