For the Caramel:
For the Bark:
Line an 8 x 8" baking dish with parchment paper.
Make the caramel sauce. Add sugar and water into a saucepan over medium low heat. Stir until sugar has dissolved, swirling to combine. Once sugar has dissolved increase heat to high. Continue to swirl occasionally. Do not stir the mixture directly. The mixture will start to bubble after a minute. As the mixture darkens to a medium-dark amber color, approximately 7 minutes, add the butter and heavy cream to saucepan. The mixture will bubble wildly. Whisk to combine (bubbles will subside upon cooling). Add the extract. Swirl again. Set aside to cool.
Melt the chocolate in a microwave safe bowl in 30-second bursts, stirring between each blitz until melted. Pour have the chocolate into the 8 x 8"pan. Smooth slightly and refrigerate for 5 minutes to cool. Pour half the caramel sauce all over the chocolate and drizzle with about 1/2 cup of the pecans. Gently press the pecans into the caramel. Refrigerate again to harden slightly, about 5 more minutes. Cover with the remaining melted chocolate. When mostly cooled, sprinkle with the remaining pecans (or to taste) and drizzle with some caramel sauce (there will be sauce left over).
Chop when cool and serve.