Preheat the oven to 350°F and line a large baking sheet with parchment paper.

Arrange the Ritz crackers in a single layer on the prepared baking sheet, keeping them close together without overlapping.

Roughly chop the pecans into a mix of small and medium pieces.

In a medium saucepan, combine the sweetened condensed milk, butter, brown sugar, and milk.

Cook over medium heat, stirring often, until the butter melts and the mixture is smooth, creamy, and glossy.

Stir in the vanilla extract, cinnamon, nutmeg, and chopped pecans.

Continue stirring for 1–2 minutes, until the mixture thickens slightly and is spoonable.

Spoon about 1 heaping teaspoon of the pecan mixture onto each cracker.

Bake for 8–10 minutes, until the topping is bubbly and slightly darker around the edges.

Let cool on the baking sheet until set, then transfer to a serving plate or storage container.