Pat the bacon shortbread dough into an 8x8-inch pan and bake at 325F for 30 minutes, until very pale golden around the edges and set. Meanwhile, in a small saucepan, simmer 1/2 cup of the ale for about 20 minutes, until it's reduced by more than half.
In a largish pot (it will bubble up) combine 1/4 cup more of the ale (from the bottle), sugars, butter, cream, syrup and salt over medium-high heat. Cook, stirring occasionally, until the mixture reaches 244F on a candy thermometer. Stir in the reduced ale and pour over the shortbread base. Let stand or chill until firm.
Melt the chocolate chips in a small bowl in the microwave, stirring until melted. Spread over the set caramel and let stand or refrigerate for 10 minutes, until set. Run a thin knife around the edge of the pan and invert the squares onto a cutting board, then cut into squares or bars with a sharp, heavy knife.