In a medium saucepan over medium heat, combine butter, brown sugar, granulated sugar, corn syrup, and water. Stir constantly until the butter is melted and the sugars are dissolved.

Bring the mixture to a boil, stirring constantly. Continue to boil for 5 minutes, or until the mixture reaches 245°F (118°C) on a candy thermometer (soft-ball stage).

Remove from heat and stir in vanilla extract and salt. Let the caramel cool completely.

Preheat oven to 350°F (175°C). Line baking sheets with parchment paper.

In a large bowl, cream together the softened butter and both sugars until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla.

In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix.

Stir in the toasted pecans. Drop rounded tablespoons of cookie dough onto the prepared baking sheets, leaving about 2 inches between each cookie.

Bake for 10-12 minutes, or until the edges are golden brown. Let the cookies cool on the baking sheets for a few minutes before transferring them to a wire rack to cool completely.

Once the cookies and caramel are completely cool, spoon a dollop of the caramel filling onto the center of each cookie.