Toast the pecans in a dry skillet over medium heat for 5 minutes to enhance their flavor.

Let the pecans cool slightly and blend with 1 cup of water until smooth, about 1-2 minutes.

Strain the blended pecan mixture through a fine mesh strainer for a smoother texture, if desired.

In a medium saucepan, combine the strained pecan mixture with the remaining 3 cups of water, milk, masa harina, sugar, vanilla extract, and salt.

Cook the mixture over medium heat, stirring constantly, until it thickens, about 10 minutes.

Taste the atole and adjust the sweetness by adding more sugar if needed.

Remove from heat and serve warm in mugs.

Garnish with a sprinkle of cinnamon or crushed pecans on top, if desired.