Combine butter, brown sugar, flour, oats, and pecans. Gather dough
into a ball, then press down to form a disk. Wrap dough in plastic
and chill in refrigerator for 20 minutes, or overnight.
Press dough evenly into a 9 1/2-inch tart pan with removable bottom.
The crust should be about 1/8-inch thick on the bottom and slightly
thicker on the sides.
Bake crust for 12 minutes, until golden brown.
Remove from oven and cool.
Make the ganache: Pour chocolate chips into mixing bowl.
In heavy saucepan, heat cream over medium-high heat until it just
begins to simmer. Remove from heat immediately and pour hot cream
over chocolate chips. Stir steadily until all chocolate is melted.
Pour 3/4 cup ganache over bottom of tart.
Refrigerate for 15 minutes.
Meanwhile, melt caramels with the cream over medium-low heat, paying
careful attention that it does not burn.
Stir in pecans.
chilled tart from refrigerator and pour caramel mixture over the
entire chocolate layer. The caramel should spread slowly and evenly
over the ganache. If necessary, even out the caramel layer very
gently with a spatula.
Return tart to refrigerator for 10 minutes.
Pour remaining 1/4 cup ganache into a pastry bag (or a sandwich
bag with a small cut at one corner). Squeeze out ganache in parallel
stripes over the caramel layer. Run a knife through the chocolate
in perpendicular or diagonal.
Yield: 10 to 12 servings
The tart can be chilled for up to three days before serving.