Prepare the Baking Sheet: Line a large baking sheet with parchment paper or a silicone baking mat.

Melt the Chocolate: Break the white chocolate into pieces and place it in a microwave-safe bowl. Microwave in 30-second intervals, stirring after each interval, until the chocolate is completely melted and smooth.

Spread the Chocolate: Pour the melted white chocolate onto the prepared baking sheet. Use a spatula to spread it into an even layer, about 1/4 inch thick.

Add Pretzels and Toppings: Immediately press the pretzels into the melted chocolate, arranging them evenly. Sprinkle the M&M's and holiday-themed sprinkles over the top.

Set the Bark: Allow the pretzel bark to sit at room temperature until the chocolate is fully set. You can also place it in the refrigerator for faster setting.

Break into Pieces: Once the chocolate is set, break the pretzel bark into pieces of your desired size.