Toast sesame seeds in a dry skillet over medium heat for 3 to 4 minutes, stirring often, until golden and fragrant.
Line an 8x8-inch pan with parchment paper, leaving overhang on two sides.
In a small saucepan, warm the date syrup and tahini together over low heat for 2 to 3 minutes, stirring until smooth and pourable. Don't let it boil.
Remove from heat and stir in the toasted sesame seeds, rolled oats, chopped nuts, salt, and vanilla until everything is fully coated.
Transfer the mixture to the prepared pan and press firmly and evenly using the back of a spoon or the bottom of a glass.
Chill in the fridge for at least 1 hour, until firm to the touch.
Lift the slab out using the parchment overhang and cut into 16 bars.