½ cup (125 mL) butter, softened
2 tbsp (30 mL) icing sugar
1½ cups (375 mL) AP flour
1½ cups (375 mL) packed brown sugar
¼ cup (60 mL) butter, melted
2 eggs, beaten
1 tbsp (15 mL) white vinegar
1 tbsp (15 mL) dark rum
1 tsp (5 mL) vanilla
1 cup (250 mL) raisins
In bowl, cream butter with icing sugar; mix in flour until it looks like small crumbs. Press into parchment paper–lined 9-inch (2.5 L) square cake pan. Bake in 350ºF (180ºC) oven until light golden, 12 to 15 minutes.
Topping: Whisk together brown sugar, butter, eggs, vinegar, rum & vanilla; stir in raisins. Pour over baked Base.
Bake in 350ºF (180ºC) oven until light golden and crust has formed but centre is still jiggly, around 35 minutes. Let cool in pan on rack. Refrigerate 1-2 hours then cut into squares.