Preheat your oven to 350 degrees. Line cookie sheets with parchment paper or silicone mats.

In a large bowl, beat the butter on medium-high speed for one minute. 

Add the powdered sugar and vanilla. Beat for a few seconds on low speed until the powdered sugar is partially mixed in. Then beat for about 2 minutes on medium-high speed, until creamy. Scrape down the sides and bottom as needed with a spatula.

Turn the mixer on to low speed, and add the flour in 1/4-cup increments.

Once all the flour has been mixed in, add the salt and chopped pecans. Turn the mixer to high and beat until the dough comes together. If the dough is not smooth after two minutes of beating, add 1-2 teaspoons of water and beat again.

Divide the dough into two portions. Roll out half the dough onto a lightly-floured surface. Make it 1/4-inch thick.

Use a pizza cutter to cut the dough into two-inch squares. Transfer the squares to your cookie sheets, spacing them about three inches apart.

Repeat with the second half of the dough.

Bake for 11-13 minutes until the edges start to brown slightly. Remove from the oven and allow to cool for five minutes on the cookie sheet before transferring to a wire rack to cool completely.

When the cookies are cool, melt your chocolate in a double boiler on the stove, or in the microwave in 15-second increments, stopping to stir after each, until completely smooth.

Dip the corner of each cookie into the melted chocolate and place on parchment paper to cool and set up.

Before chocolate has completely dried, sprinkle with toffee bits. Allow to dry completely, then serve or store in an airtight container for up to one week.