Toss the pear, pear juice, brandy, granulated sugar, lemon juice and salt in a medium bowl. Cover with plastic wrap; set aside. Beat the mascarpone, heavy cream, confectioners' sugar, vanilla and white pepper in a stand mixer fitted with the paddle attachment (or in a large bowl with a hand mixer) on medium-low speed until combined, about 1 minute. Increase the mixer speed to medium high and beat until light and fluffy, 1 to 2 more minutes (do not overbeat). Line a 9-by-5-inch loaf pan with plastic wrap, leaving a 2-inch overhang on all sides. Arrange 9 ladyfingers in the bottom of the pan in a single layer. Top with half of the pears and drizzle with 3 tablespoons of the pear liquid. Spread 1 cup of the mascarpone mixture over the pears. Repeat with 9 more ladyfingers, the remaining pears, 3 tablespoons of the pear liquid and 1 cup mascarpone mixture. Top with the remaining 9 ladyfingers and drizzle with 3 tablespoons of the pear liquid. Cover with plastic wrap and refrigerate at least 8 hours or overnight. (Transfer the remaining mascarpone mixture to an airtight container and refrigerate until ready to serve.) To serve, let the reserved mascarpone mixture come to room temperature. Lift the tiramisu out of the pan using the plastic wrap and invert onto a platter; remove the plastic wrap. Cover the top and sides with the remaining mascarpone mixture.