Any sort of jam you have on hand will work in this recipe, so don’t feel boxed in by the title.

Preheat the oven to 375°F. Grease a 13 × 9 × 2-inch baking pan and line with parchment paper so it extends over the 2 long sides.

Whisk together in a medium bowl:

Add:

Using a pastry blender or your fingertips, cut or rub in the butter until it is the size of small peas (or, combine the flour, sugar, and salt in a food processor, sprinkle the butter over the top, and process until well blended). Stir together in a small bowl:

Add the milk mixture to the flour mixture and stir or pulse until the dough begins to hold together. Press two-thirds of the dough into the bottom of the prepared pan. Bake until barely firm in the center, 12 to 15 minutes. Set the pan on a rack (leave the oven on) and spread evenly over the hot crust:

Add to the reserved dough:

Work in with your hands until just combined. Sprinkle the streusel evenly over the jam, leaving some clumps large and some small. Bake until the streusel is browned and the raspberry jam is bubbling, 25 to 30 minutes. Let cool completely in the pan on a rack before cutting into bars.