Preheat the oven to 350°F (175°C). Line a cookie sheet with parchment paper or lightly grease it.
Thaw the frozen spinach and squeeze out as much liquid as possible using paper towels or a clean kitchen towel.
In a medium bowl, combine the squeezed spinach, crumbled stuffing mix, eggs, grated Parmesan, thyme, melted butter, crushed garlic, and salt and pepper. Mix until evenly combined.
Refrigerate the mixture for 20 minutes to firm up so it is easier to shape.
Remove the bowl from the refrigerator and roll the mixture into 1-inch balls; you should get about 40 balls.
Place the spinach balls on the prepared cookie sheet, leaving a little space between them, and bake for 15 to 20 minutes until heated through and lightly golden.
Remove from the oven and serve warm.