Preheat your oven to 350 degrees F. Prepare an 8x8 pan by lining it with parchment paper and folding it over the edges of the pan to make for easy removal and cleanup. (If you don't have parchment paper, use foil and grease it well.)
Cut up the dates into small pieces with kitchen scissors. (They're really sticky to chop with a knife and don't do well in a food processor or blender.) It's best to cut a pitted date in half the long way, then cut those pieces in half the long way again. Then, snip each strip into pieces.
If starting with walnut halves, chop them until you have one cup.
In a glass bowl or other microwave-safe bowl, melt your butter in the microwave, covering it with wax paper to prevent splashing. Stir in the sugar.
Add the eggs and vanilla to your bowl and mix with a spoon until blended. Add the flour and salt and stir. Stir in the dates and nuts until blended.
Pour the batter into your baking pan and use a spatula to even it out. Bake for 35-40 minutes, or until the top is golden brown. A toothpick or cake tester inserted in the center should come out clean.
Let the pan cool on a rack for 10 minutes. Then lift out the Chinese Chews by grasping the parchment paper and transferring everything to a cutting board. Cut into squares (I did 16 large ones, but smaller squares work well, since they are rich tasting.)
If you're not planning to freeze them, dust with confectioner's sugar. Transfer the bars to a rack to finish cooling. They taste best when completely cooled.
Store at room temperature in an airtight container. You can freeze them without the confectioner's sugar and add the sugar when they are thawed.
You can double the recipe for a 9x13 pan. You may need to bake it for a few minutes longer. When the top is golden brown, insert a toothpick in the center to see if it comes out clean.