Beat the butter and brown sugar together in a mixing bowl until fluffy. Add milk and vanilla and beat an additional minute. Beat in the salt and flour until combined. By hand, stir in the mini chocolate chips.
Refrigerate dough for at least half an hour to make it easier to handle, if desired. Divide dough in half and roll out each portion into a rectangle on a lightly floured surface. (If the dough starts to come apart as you roll, you can pat it back together with your hands.) Transfer each half to a cookie sheet.
Combine the white chocolate chips and sweetened condensed milk in a small saucepan. Cook over low heat, stirring constantly, until chocolate is melted and mixture is smooth. Remove from heat and stir in the almond extract.
Spread half the white chocolate mixture onto the long half of each portion of dough, leaving about a 1/2 inch margin on the edges.
Fold the other half of the dough over the top of each section and press together to seal the edges.
Bake at 350 degrees for 15-20 minutes, until set and lightly golden brown. Cool on the cookie sheets for 15 minutes. Slice the blocks into 1/2 inch slices.
Transfer slices to a wire rack to finish cooling completely.
In addition to looking great on a cookie platter, these cookies are also great for gift-giving since their unique shape means lots of fun packaging ideas. A handful placed lengthwise in a coffee mug looks stunning!