Toss the dates in the liquor and let them sit for a few hours.
Preheat the oven to 350ºF (175ºC). Line an 8 (23 cm) square pan with foil and coat the inside with non-stick spray.
In a small bowl, whisk together the flour and baking powder.
In a large bowl, whisk together the sugar, salt, and eggs until smooth. Mix in the butter, hot water, and vanilla, then stir in the flour mixture. Use a spatula to stir in the dates (and any liquid) and the pecans.
Scrape the mixture into the prepared pan and bake for 25 to 30 minutes, or until the top is golden brown and a toothpick inserted in the center comes out clean.
Let date bars cool, then lift out the bars. Peel away the foil and cut into squares.