Melt sugar in a large saucepan with cream and butter, stirring constantly.
Once sugar is dissolved, boil the mixture rapidly, continuing to
stir until it reaches soft-ball stage (236 degrees F on a candy
Remove from heat, beat in the chopped pecans and vanilla
extract, and continue to beat with a wire whisk until mixture is
creamy. Immediately pour it onto a baking sheet to cool.
When mixture is cool, tear off pieces and chop them in a food processor
or by hand.
Press the praline mixture into the pre-baked tart crust,
making an even layer.
Before serving, add bourbon to the whipped cream and spread on top
of the praline layer.
Decorate top with pecan halves lightly toasted
for 5 to 10 minutes in a hot skillet or oven.