Preheat your oven to 400 degrees F. Prepare two sheet pans (if using bacon, or only 1 sheet pan if not using bacon) by covering them with aluminum foil. Spray a mini muffin pan with nonstick spray and set it aside.
If using bacon, lay the strips flat on one of the sheet pans and bake them in the oven for 15 minutes, or until bacon is browned and crispy.
Remove the pan from the oven and move the bacon onto a paper towel-lined plate to absorb any excess grease. When the bacon is cool to touch, crumble it into small pieces. Set crumbled bacon aside.
Chop the pecans into small pieces. Then, add them to the other sheet pan. Toast pecans in the oven for about 5 minutes, watching carefully so they don't burn. Remove from the oven and set aside.
Lower the oven temperature to 350 degrees F.
Add the butter to a large microwave-safe mixing bowl, microwave in 30 second intervals until completely melted.
Add the toasted pecans, crumbled bacon, brown sugar, bourbon, and salt to the melted butter. Stir to combine it all.
Cut brie into small cubes, just large enough to fit in a mini muffin pan. Set aside.
Lay out the phyllo dough and use a circular cookie cutter to cut the dough into circles a bit larger than the holes of the muffin pan. You should end up with 18 even-sized circles. (If you don't have a cookie cutter, you can also use a knife to cut the dough into squares instead. Or, see the note below on using pre-made phyllo cups.)
Once the dough is cut into circles, separate the sheets in half so that there are 9 sheets each, and carefully press them into each muffin cup.
Place a cube of brie into each phyllo shell. Then, top it with a mound of the pecan filling. You will end up with 36 bites total.
Place the muffin pan in the oven and bake for 15 to 20 minutes, or until the phyllo is golden brown and the pecans are slightly caramelized.
To serve, remove the bites from the oven and place them on a large serving tray. Top them with diced strawberries and serve them warm for a bite of perfectly melty brie.