Heat the oven to 350°F (177°C) and toast the pecan halves in an even layer on a baking sheet or jelly roll pan for 8 to 10 minutes, moving them around frequently. Stop when they smell nutty and look slightly darker; alternatively, toast them in a large saucepan over medium-high heat for about 5 minutes, stirring frequently.
Take the toasted pecans off the heat and leave them to cool. The nuts should lose their oven heat before you chop them.
Combine the unwrapped caramels and heavy cream in a medium microwave-safe bowl, then microwave on HIGH in 20-second bursts, stirring between bursts, until smooth. The mixture may initially look separated or barely changed, but continued heating and stirring will bring it together; let it cool slightly once no lumps remain.
Cover two large baking sheets with parchment paper. The lined surfaces will support the soft clusters through portioning and chilling.
Chop the cooled pecans coarsely and fold them into the slightly cooled caramel with a large spatula. Keep folding until nuts appear throughout the mixture rather than collecting in one area.
Portion tablespoon-size mounds onto the lined sheets with a spoon or #50 cookie scoop, placing 8 on each pan in 4 rows of 2. Leave enough space between mounds to cut a separate parchment square around each candy later.
Set the portioned clusters aside and melt the milk chocolate chips gently in the microwave, on the stovetop, or in a double boiler. Stir until the chocolate flows smoothly without remaining chip-shaped lumps.
Spoon 2 to 3 teaspoons of melted chocolate over each pecan-caramel mound, using a teaspoon-size scoop if helpful. A sweep with the back of the scoop can leave an optional swirl across the smooth topping.
Let the chocolate firm, then chill the sheets in the refrigerator for about 30 minutes or the freezer for about 10 minutes to make handling easier. The topping should feel set, although the caramel underneath will remain soft and gooey.
Cut the parchment around the firm candies into individual squares and transfer the pieces, still on their squares, to a covered container in the refrigerator. Each paper base supports the sticky filling without requiring you to peel it away.