Preheat oven to 375°F (190°C). Lightly grease a standard 12-cup muffin tin with olive oil or cooking spray.

In a small bowl, combine the finely chopped walnuts (or pistachios) with the ground cinnamon.

Lay one sheet of phyllo pastry on a clean, dry surface. Lightly brush with olive oil and sprinkle a thin, even layer of the nut-cinnamon mixture across it. Place a second phyllo sheet directly on top, brush with oil, and sprinkle with nuts. Repeat until you have stacked 4 layers.

Using a sharp knife or pizza cutter, cut the layered dough stack into 12 equal squares. Gently press each square down into the muffin tin cups, letting the corners flare outward naturally.

Bake for 12 to 15 minutes until the pastry edges are deep golden brown and crisp. Remove from oven and cool completely in the tin.

In a food processor, combine drained feta cheese, Greek yogurt, 1 tablespoon olive oil, lemon zest, and garlic powder. Process for 2 to 3 minutes, scraping down sides as needed, until pureed into a velvet-smooth white cream. Fold in fresh thyme.

Transfer whipped feta into a piping bag fitted with a wide star tip.

Carefully lift cooled phyllo cups out of the tin and arrange on a serving platter. Pipe a generous star mound of cold whipped feta into each shell. Top liberally with crushed pistachios.

Drizzle warm honey over the top just before serving so it cascades down the sides. Serve immediately.