Grilled pears

This wknd while flipping channels I ended up watching PBS; Barbecue America; (even though I don't own a BBQ) I figure I can make these in the oven.
My question is does any one know what cheese I might be able to substitute since my local market doesn't carry Mascarpone.

Marinate:
6 pears, firm but ripe, seeds removed
3/4 cup Grand Marinier
2 Tablespoon dark brown sugar
1 teaspoon vanilla extract

Mascarpone Filling:
1 1/4 cups mascarpone cheese
6 pecan shortbread cookies, crushed
1/2 cup Grand Marinier

Marinate pears overnight, or for at least 4 hours in a sealable plastic bag.

Drain pears and place on oiled hot grill just long enough to get grill marks on both sides, appx. 2 min. per side.

While pears are grilling mix filling.
Just before serving add the mascarpone-cookie mixture to each pear half.
Place back on the grill for an additional 2 minutes rounded side down.
Serve w/additional cookies or ice cream.
barbecueamerica.com